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Merge branch 'linux-next' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad...
[zen-stable.git] / fs / btrfs / disk-io.c
blob632f8f3cc9db67f4173ca591b1b66d9ed898627f
1 /*
2 * Copyright (C) 2007 Oracle. All rights reserved.
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public
6 * License v2 as published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
12 *
13 * You should have received a copy of the GNU General Public
14 * License along with this program; if not, write to the
15 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
16 * Boston, MA 021110-1307, USA.
17 */
18
19 #include <linux/fs.h>
20 #include <linux/blkdev.h>
21 #include <linux/scatterlist.h>
22 #include <linux/swap.h>
23 #include <linux/radix-tree.h>
24 #include <linux/writeback.h>
25 #include <linux/buffer_head.h>
26 #include <linux/workqueue.h>
27 #include <linux/kthread.h>
28 #include <linux/freezer.h>
29 #include <linux/crc32c.h>
30 #include <linux/slab.h>
31 #include <linux/migrate.h>
32 #include <linux/ratelimit.h>
33 #include <asm/unaligned.h>
34 #include "compat.h"
35 #include "ctree.h"
36 #include "disk-io.h"
37 #include "transaction.h"
38 #include "btrfs_inode.h"
39 #include "volumes.h"
40 #include "print-tree.h"
41 #include "async-thread.h"
42 #include "locking.h"
43 #include "tree-log.h"
44 #include "free-space-cache.h"
45 #include "inode-map.h"
46
47 static struct extent_io_ops btree_extent_io_ops;
48 static void end_workqueue_fn(struct btrfs_work *work);
49 static void free_fs_root(struct btrfs_root *root);
50 static void btrfs_check_super_valid(struct btrfs_fs_info *fs_info,
51 int read_only);
52 static int btrfs_destroy_ordered_operations(struct btrfs_root *root);
53 static int btrfs_destroy_ordered_extents(struct btrfs_root *root);
54 static int btrfs_destroy_delayed_refs(struct btrfs_transaction *trans,
55 struct btrfs_root *root);
56 static int btrfs_destroy_pending_snapshots(struct btrfs_transaction *t);
57 static int btrfs_destroy_delalloc_inodes(struct btrfs_root *root);
58 static int btrfs_destroy_marked_extents(struct btrfs_root *root,
59 struct extent_io_tree *dirty_pages,
60 int mark);
61 static int btrfs_destroy_pinned_extent(struct btrfs_root *root,
62 struct extent_io_tree *pinned_extents);
63 static int btrfs_cleanup_transaction(struct btrfs_root *root);
64
65 /*
66 * end_io_wq structs are used to do processing in task context when an IO is
67 * complete. This is used during reads to verify checksums, and it is used
68 * by writes to insert metadata for new file extents after IO is complete.
69 */
70 struct end_io_wq {
71 struct bio *bio;
72 bio_end_io_t *end_io;
73 void *private;
74 struct btrfs_fs_info *info;
75 int error;
76 int metadata;
77 struct list_head list;
78 struct btrfs_work work;
79 };
80
81 /*
82 * async submit bios are used to offload expensive checksumming
83 * onto the worker threads. They checksum file and metadata bios
84 * just before they are sent down the IO stack.
85 */
86 struct async_submit_bio {
87 struct inode *inode;
88 struct bio *bio;
89 struct list_head list;
90 extent_submit_bio_hook_t *submit_bio_start;
91 extent_submit_bio_hook_t *submit_bio_done;
92 int rw;
93 int mirror_num;
94 unsigned long bio_flags;
95 /*
96 * bio_offset is optional, can be used if the pages in the bio
97 * can't tell us where in the file the bio should go
98 */
99 u64 bio_offset;
100 struct btrfs_work work;
101 };
102
103 /*
104 * Lockdep class keys for extent_buffer->lock's in this root. For a given
105 * eb, the lockdep key is determined by the btrfs_root it belongs to and
106 * the level the eb occupies in the tree.
107 *
108 * Different roots are used for different purposes and may nest inside each
109 * other and they require separate keysets. As lockdep keys should be
110 * static, assign keysets according to the purpose of the root as indicated
111 * by btrfs_root->objectid. This ensures that all special purpose roots
112 * have separate keysets.
113 *
114 * Lock-nesting across peer nodes is always done with the immediate parent
115 * node locked thus preventing deadlock. As lockdep doesn't know this, use
116 * subclass to avoid triggering lockdep warning in such cases.
117 *
118 * The key is set by the readpage_end_io_hook after the buffer has passed
119 * csum validation but before the pages are unlocked. It is also set by
120 * btrfs_init_new_buffer on freshly allocated blocks.
121 *
122 * We also add a check to make sure the highest level of the tree is the
123 * same as our lockdep setup here. If BTRFS_MAX_LEVEL changes, this code
124 * needs update as well.
125 */
126 #ifdef CONFIG_DEBUG_LOCK_ALLOC
127 # if BTRFS_MAX_LEVEL != 8
128 # error
129 # endif
130
131 static struct btrfs_lockdep_keyset {
132 u64 id; /* root objectid */
133 const char *name_stem; /* lock name stem */
134 char names[BTRFS_MAX_LEVEL + 1][20];
135 struct lock_class_key keys[BTRFS_MAX_LEVEL + 1];
136 } btrfs_lockdep_keysets[] = {
137 { .id = BTRFS_ROOT_TREE_OBJECTID, .name_stem = "root" },
138 { .id = BTRFS_EXTENT_TREE_OBJECTID, .name_stem = "extent" },
139 { .id = BTRFS_CHUNK_TREE_OBJECTID, .name_stem = "chunk" },
140 { .id = BTRFS_DEV_TREE_OBJECTID, .name_stem = "dev" },
141 { .id = BTRFS_FS_TREE_OBJECTID, .name_stem = "fs" },
142 { .id = BTRFS_CSUM_TREE_OBJECTID, .name_stem = "csum" },
143 { .id = BTRFS_ORPHAN_OBJECTID, .name_stem = "orphan" },
144 { .id = BTRFS_TREE_LOG_OBJECTID, .name_stem = "log" },
145 { .id = BTRFS_TREE_RELOC_OBJECTID, .name_stem = "treloc" },
146 { .id = BTRFS_DATA_RELOC_TREE_OBJECTID, .name_stem = "dreloc" },
147 { .id = 0, .name_stem = "tree" },
148 };
149
150 void __init btrfs_init_lockdep(void)
151 {
152 int i, j;
153
154 /* initialize lockdep class names */
155 for (i = 0; i < ARRAY_SIZE(btrfs_lockdep_keysets); i++) {
156 struct btrfs_lockdep_keyset *ks = &btrfs_lockdep_keysets[i];
157
158 for (j = 0; j < ARRAY_SIZE(ks->names); j++)
159 snprintf(ks->names[j], sizeof(ks->names[j]),
160 "btrfs-%s-%02d", ks->name_stem, j);
161 }
162 }
163
164 void btrfs_set_buffer_lockdep_class(u64 objectid, struct extent_buffer *eb,
165 int level)
166 {
167 struct btrfs_lockdep_keyset *ks;
168
169 BUG_ON(level >= ARRAY_SIZE(ks->keys));
170
171 /* find the matching keyset, id 0 is the default entry */
172 for (ks = btrfs_lockdep_keysets; ks->id; ks++)
173 if (ks->id == objectid)
174 break;
175
176 lockdep_set_class_and_name(&eb->lock,
177 &ks->keys[level], ks->names[level]);
178 }
179
180 #endif
181
182 /*
183 * extents on the btree inode are pretty simple, there's one extent
184 * that covers the entire device
185 */
186 static struct extent_map *btree_get_extent(struct inode *inode,
187 struct page *page, size_t pg_offset, u64 start, u64 len,
188 int create)
189 {
190 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
191 struct extent_map *em;
192 int ret;
193
194 read_lock(&em_tree->lock);
195 em = lookup_extent_mapping(em_tree, start, len);
196 if (em) {
197 em->bdev =
198 BTRFS_I(inode)->root->fs_info->fs_devices->latest_bdev;
199 read_unlock(&em_tree->lock);
200 goto out;
201 }
202 read_unlock(&em_tree->lock);
203
204 em = alloc_extent_map();
205 if (!em) {
206 em = ERR_PTR(-ENOMEM);
207 goto out;
208 }
209 em->start = 0;
210 em->len = (u64)-1;
211 em->block_len = (u64)-1;
212 em->block_start = 0;
213 em->bdev = BTRFS_I(inode)->root->fs_info->fs_devices->latest_bdev;
214
215 write_lock(&em_tree->lock);
216 ret = add_extent_mapping(em_tree, em);
217 if (ret == -EEXIST) {
218 u64 failed_start = em->start;
219 u64 failed_len = em->len;
220
221 free_extent_map(em);
222 em = lookup_extent_mapping(em_tree, start, len);
223 if (em) {
224 ret = 0;
225 } else {
226 em = lookup_extent_mapping(em_tree, failed_start,
227 failed_len);
228 ret = -EIO;
229 }
230 } else if (ret) {
231 free_extent_map(em);
232 em = NULL;
233 }
234 write_unlock(&em_tree->lock);
235
236 if (ret)
237 em = ERR_PTR(ret);
238 out:
239 return em;
240 }
241
242 u32 btrfs_csum_data(struct btrfs_root *root, char *data, u32 seed, size_t len)
243 {
244 return crc32c(seed, data, len);
245 }
246
247 void btrfs_csum_final(u32 crc, char *result)
248 {
249 put_unaligned_le32(~crc, result);
250 }
251
252 /*
253 * compute the csum for a btree block, and either verify it or write it
254 * into the csum field of the block.
255 */
256 static int csum_tree_block(struct btrfs_root *root, struct extent_buffer *buf,
257 int verify)
258 {
259 u16 csum_size = btrfs_super_csum_size(root->fs_info->super_copy);
260 char *result = NULL;
261 unsigned long len;
262 unsigned long cur_len;
263 unsigned long offset = BTRFS_CSUM_SIZE;
264 char *kaddr;
265 unsigned long map_start;
266 unsigned long map_len;
267 int err;
268 u32 crc = ~(u32)0;
269 unsigned long inline_result;
270
271 len = buf->len - offset;
272 while (len > 0) {
273 err = map_private_extent_buffer(buf, offset, 32,
274 &kaddr, &map_start, &map_len);
275 if (err)
276 return 1;
277 cur_len = min(len, map_len - (offset - map_start));
278 crc = btrfs_csum_data(root, kaddr + offset - map_start,
279 crc, cur_len);
280 len -= cur_len;
281 offset += cur_len;
282 }
283 if (csum_size > sizeof(inline_result)) {
284 result = kzalloc(csum_size * sizeof(char), GFP_NOFS);
285 if (!result)
286 return 1;
287 } else {
288 result = (char *)&inline_result;
289 }
290
291 btrfs_csum_final(crc, result);
292
293 if (verify) {
294 if (memcmp_extent_buffer(buf, result, 0, csum_size)) {
295 u32 val;
296 u32 found = 0;
297 memcpy(&found, result, csum_size);
298
299 read_extent_buffer(buf, &val, 0, csum_size);
300 printk_ratelimited(KERN_INFO "btrfs: %s checksum verify "
301 "failed on %llu wanted %X found %X "
302 "level %d\n",
303 root->fs_info->sb->s_id,
304 (unsigned long long)buf->start, val, found,
305 btrfs_header_level(buf));
306 if (result != (char *)&inline_result)
307 kfree(result);
308 return 1;
309 }
310 } else {
311 write_extent_buffer(buf, result, 0, csum_size);
312 }
313 if (result != (char *)&inline_result)
314 kfree(result);
315 return 0;
316 }
317
318 /*
319 * we can't consider a given block up to date unless the transid of the
320 * block matches the transid in the parent node's pointer. This is how we
321 * detect blocks that either didn't get written at all or got written
322 * in the wrong place.
323 */
324 static int verify_parent_transid(struct extent_io_tree *io_tree,
325 struct extent_buffer *eb, u64 parent_transid)
326 {
327 struct extent_state *cached_state = NULL;
328 int ret;
329
330 if (!parent_transid || btrfs_header_generation(eb) == parent_transid)
331 return 0;
332
333 lock_extent_bits(io_tree, eb->start, eb->start + eb->len - 1,
334 0, &cached_state, GFP_NOFS);
335 if (extent_buffer_uptodate(io_tree, eb, cached_state) &&
336 btrfs_header_generation(eb) == parent_transid) {
337 ret = 0;
338 goto out;
339 }
340 printk_ratelimited("parent transid verify failed on %llu wanted %llu "
341 "found %llu\n",
342 (unsigned long long)eb->start,
343 (unsigned long long)parent_transid,
344 (unsigned long long)btrfs_header_generation(eb));
345 ret = 1;
346 clear_extent_buffer_uptodate(io_tree, eb, &cached_state);
347 out:
348 unlock_extent_cached(io_tree, eb->start, eb->start + eb->len - 1,
349 &cached_state, GFP_NOFS);
350 return ret;
351 }
352
353 /*
354 * helper to read a given tree block, doing retries as required when
355 * the checksums don't match and we have alternate mirrors to try.
356 */
357 static int btree_read_extent_buffer_pages(struct btrfs_root *root,
358 struct extent_buffer *eb,
359 u64 start, u64 parent_transid)
360 {
361 struct extent_io_tree *io_tree;
362 int ret;
363 int num_copies = 0;
364 int mirror_num = 0;
365
366 clear_bit(EXTENT_BUFFER_CORRUPT, &eb->bflags);
367 io_tree = &BTRFS_I(root->fs_info->btree_inode)->io_tree;
368 while (1) {
369 ret = read_extent_buffer_pages(io_tree, eb, start,
370 WAIT_COMPLETE,
371 btree_get_extent, mirror_num);
372 if (!ret &&
373 !verify_parent_transid(io_tree, eb, parent_transid))
374 return ret;
375
376 /*
377 * This buffer's crc is fine, but its contents are corrupted, so
378 * there is no reason to read the other copies, they won't be
379 * any less wrong.
380 */
381 if (test_bit(EXTENT_BUFFER_CORRUPT, &eb->bflags))
382 return ret;
383
384 num_copies = btrfs_num_copies(&root->fs_info->mapping_tree,
385 eb->start, eb->len);
386 if (num_copies == 1)
387 return ret;
388
389 mirror_num++;
390 if (mirror_num > num_copies)
391 return ret;
392 }
393 return -EIO;
394 }
395
396 /*
397 * checksum a dirty tree block before IO. This has extra checks to make sure
398 * we only fill in the checksum field in the first page of a multi-page block
399 */
400
401 static int csum_dirty_buffer(struct btrfs_root *root, struct page *page)
402 {
403 struct extent_io_tree *tree;
404 u64 start = (u64)page->index << PAGE_CACHE_SHIFT;
405 u64 found_start;
406 unsigned long len;
407 struct extent_buffer *eb;
408 int ret;
409
410 tree = &BTRFS_I(page->mapping->host)->io_tree;
411
412 if (page->private == EXTENT_PAGE_PRIVATE) {
413 WARN_ON(1);
414 goto out;
415 }
416 if (!page->private) {
417 WARN_ON(1);
418 goto out;
419 }
420 len = page->private >> 2;
421 WARN_ON(len == 0);
422
423 eb = alloc_extent_buffer(tree, start, len, page);
424 if (eb == NULL) {
425 WARN_ON(1);
426 goto out;
427 }
428 ret = btree_read_extent_buffer_pages(root, eb, start + PAGE_CACHE_SIZE,
429 btrfs_header_generation(eb));
430 BUG_ON(ret);
431 WARN_ON(!btrfs_header_flag(eb, BTRFS_HEADER_FLAG_WRITTEN));
432
433 found_start = btrfs_header_bytenr(eb);
434 if (found_start != start) {
435 WARN_ON(1);
436 goto err;
437 }
438 if (eb->first_page != page) {
439 WARN_ON(1);
440 goto err;
441 }
442 if (!PageUptodate(page)) {
443 WARN_ON(1);
444 goto err;
445 }
446 csum_tree_block(root, eb, 0);
447 err:
448 free_extent_buffer(eb);
449 out:
450 return 0;
451 }
452
453 static int check_tree_block_fsid(struct btrfs_root *root,
454 struct extent_buffer *eb)
455 {
456 struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices;
457 u8 fsid[BTRFS_UUID_SIZE];
458 int ret = 1;
459
460 read_extent_buffer(eb, fsid, (unsigned long)btrfs_header_fsid(eb),
461 BTRFS_FSID_SIZE);
462 while (fs_devices) {
463 if (!memcmp(fsid, fs_devices->fsid, BTRFS_FSID_SIZE)) {
464 ret = 0;
465 break;
466 }
467 fs_devices = fs_devices->seed;
468 }
469 return ret;
470 }
471
472 #define CORRUPT(reason, eb, root, slot) \
473 printk(KERN_CRIT "btrfs: corrupt leaf, %s: block=%llu," \
474 "root=%llu, slot=%d\n", reason, \
475 (unsigned long long)btrfs_header_bytenr(eb), \
476 (unsigned long long)root->objectid, slot)
477
478 static noinline int check_leaf(struct btrfs_root *root,
479 struct extent_buffer *leaf)
480 {
481 struct btrfs_key key;
482 struct btrfs_key leaf_key;
483 u32 nritems = btrfs_header_nritems(leaf);
484 int slot;
485
486 if (nritems == 0)
487 return 0;
488
489 /* Check the 0 item */
490 if (btrfs_item_offset_nr(leaf, 0) + btrfs_item_size_nr(leaf, 0) !=
491 BTRFS_LEAF_DATA_SIZE(root)) {
492 CORRUPT("invalid item offset size pair", leaf, root, 0);
493 return -EIO;
494 }
495
496 /*
497 * Check to make sure each items keys are in the correct order and their
498 * offsets make sense. We only have to loop through nritems-1 because
499 * we check the current slot against the next slot, which verifies the
500 * next slot's offset+size makes sense and that the current's slot
501 * offset is correct.
502 */
503 for (slot = 0; slot < nritems - 1; slot++) {
504 btrfs_item_key_to_cpu(leaf, &leaf_key, slot);
505 btrfs_item_key_to_cpu(leaf, &key, slot + 1);
506
507 /* Make sure the keys are in the right order */
508 if (btrfs_comp_cpu_keys(&leaf_key, &key) >= 0) {
509 CORRUPT("bad key order", leaf, root, slot);
510 return -EIO;
511 }
512
513 /*
514 * Make sure the offset and ends are right, remember that the
515 * item data starts at the end of the leaf and grows towards the
516 * front.
517 */
518 if (btrfs_item_offset_nr(leaf, slot) !=
519 btrfs_item_end_nr(leaf, slot + 1)) {
520 CORRUPT("slot offset bad", leaf, root, slot);
521 return -EIO;
522 }
523
524 /*
525 * Check to make sure that we don't point outside of the leaf,
526 * just incase all the items are consistent to eachother, but
527 * all point outside of the leaf.
528 */
529 if (btrfs_item_end_nr(leaf, slot) >
530 BTRFS_LEAF_DATA_SIZE(root)) {
531 CORRUPT("slot end outside of leaf", leaf, root, slot);
532 return -EIO;
533 }
534 }
535
536 return 0;
537 }
538
539 static int btree_readpage_end_io_hook(struct page *page, u64 start, u64 end,
540 struct extent_state *state)
541 {
542 struct extent_io_tree *tree;
543 u64 found_start;
544 int found_level;
545 unsigned long len;
546 struct extent_buffer *eb;
547 struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
548 int ret = 0;
549
550 tree = &BTRFS_I(page->mapping->host)->io_tree;
551 if (page->private == EXTENT_PAGE_PRIVATE)
552 goto out;
553 if (!page->private)
554 goto out;
555
556 len = page->private >> 2;
557 WARN_ON(len == 0);
558
559 eb = alloc_extent_buffer(tree, start, len, page);
560 if (eb == NULL) {
561 ret = -EIO;
562 goto out;
563 }
564
565 found_start = btrfs_header_bytenr(eb);
566 if (found_start != start) {
567 printk_ratelimited(KERN_INFO "btrfs bad tree block start "
568 "%llu %llu\n",
569 (unsigned long long)found_start,
570 (unsigned long long)eb->start);
571 ret = -EIO;
572 goto err;
573 }
574 if (eb->first_page != page) {
575 printk(KERN_INFO "btrfs bad first page %lu %lu\n",
576 eb->first_page->index, page->index);
577 WARN_ON(1);
578 ret = -EIO;
579 goto err;
580 }
581 if (check_tree_block_fsid(root, eb)) {
582 printk_ratelimited(KERN_INFO "btrfs bad fsid on block %llu\n",
583 (unsigned long long)eb->start);
584 ret = -EIO;
585 goto err;
586 }
587 found_level = btrfs_header_level(eb);
588
589 btrfs_set_buffer_lockdep_class(btrfs_header_owner(eb),
590 eb, found_level);
591
592 ret = csum_tree_block(root, eb, 1);
593 if (ret) {
594 ret = -EIO;
595 goto err;
596 }
597
598 /*
599 * If this is a leaf block and it is corrupt, set the corrupt bit so
600 * that we don't try and read the other copies of this block, just
601 * return -EIO.
602 */
603 if (found_level == 0 && check_leaf(root, eb)) {
604 set_bit(EXTENT_BUFFER_CORRUPT, &eb->bflags);
605 ret = -EIO;
606 }
607
608 end = min_t(u64, eb->len, PAGE_CACHE_SIZE);
609 end = eb->start + end - 1;
610 err:
611 if (test_bit(EXTENT_BUFFER_READAHEAD, &eb->bflags)) {
612 clear_bit(EXTENT_BUFFER_READAHEAD, &eb->bflags);
613 btree_readahead_hook(root, eb, eb->start, ret);
614 }
615
616 free_extent_buffer(eb);
617 out:
618 return ret;
619 }
620
621 static int btree_io_failed_hook(struct bio *failed_bio,
622 struct page *page, u64 start, u64 end,
623 int mirror_num, struct extent_state *state)
624 {
625 struct extent_io_tree *tree;
626 unsigned long len;
627 struct extent_buffer *eb;
628 struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
629
630 tree = &BTRFS_I(page->mapping->host)->io_tree;
631 if (page->private == EXTENT_PAGE_PRIVATE)
632 goto out;
633 if (!page->private)
634 goto out;
635
636 len = page->private >> 2;
637 WARN_ON(len == 0);
638
639 eb = alloc_extent_buffer(tree, start, len, page);
640 if (eb == NULL)
641 goto out;
642
643 if (test_bit(EXTENT_BUFFER_READAHEAD, &eb->bflags)) {
644 clear_bit(EXTENT_BUFFER_READAHEAD, &eb->bflags);
645 btree_readahead_hook(root, eb, eb->start, -EIO);
646 }
647 free_extent_buffer(eb);
648
649 out:
650 return -EIO; /* we fixed nothing */
651 }
652
653 static void end_workqueue_bio(struct bio *bio, int err)
654 {
655 struct end_io_wq *end_io_wq = bio->bi_private;
656 struct btrfs_fs_info *fs_info;
657
658 fs_info = end_io_wq->info;
659 end_io_wq->error = err;
660 end_io_wq->work.func = end_workqueue_fn;
661 end_io_wq->work.flags = 0;
662
663 if (bio->bi_rw & REQ_WRITE) {
664 if (end_io_wq->metadata == 1)
665 btrfs_queue_worker(&fs_info->endio_meta_write_workers,
666 &end_io_wq->work);
667 else if (end_io_wq->metadata == 2)
668 btrfs_queue_worker(&fs_info->endio_freespace_worker,
669 &end_io_wq->work);
670 else
671 btrfs_queue_worker(&fs_info->endio_write_workers,
672 &end_io_wq->work);
673 } else {
674 if (end_io_wq->metadata)
675 btrfs_queue_worker(&fs_info->endio_meta_workers,
676 &end_io_wq->work);
677 else
678 btrfs_queue_worker(&fs_info->endio_workers,
679 &end_io_wq->work);
680 }
681 }
682
683 /*
684 * For the metadata arg you want
685 *
686 * 0 - if data
687 * 1 - if normal metadta
688 * 2 - if writing to the free space cache area
689 */
690 int btrfs_bio_wq_end_io(struct btrfs_fs_info *info, struct bio *bio,
691 int metadata)
692 {
693 struct end_io_wq *end_io_wq;
694 end_io_wq = kmalloc(sizeof(*end_io_wq), GFP_NOFS);
695 if (!end_io_wq)
696 return -ENOMEM;
697
698 end_io_wq->private = bio->bi_private;
699 end_io_wq->end_io = bio->bi_end_io;
700 end_io_wq->info = info;
701 end_io_wq->error = 0;
702 end_io_wq->bio = bio;
703 end_io_wq->metadata = metadata;
704
705 bio->bi_private = end_io_wq;
706 bio->bi_end_io = end_workqueue_bio;
707 return 0;
708 }
709
710 unsigned long btrfs_async_submit_limit(struct btrfs_fs_info *info)
711 {
712 unsigned long limit = min_t(unsigned long,
713 info->workers.max_workers,
714 info->fs_devices->open_devices);
715 return 256 * limit;
716 }
717
718 static void run_one_async_start(struct btrfs_work *work)
719 {
720 struct async_submit_bio *async;
721
722 async = container_of(work, struct async_submit_bio, work);
723 async->submit_bio_start(async->inode, async->rw, async->bio,
724 async->mirror_num, async->bio_flags,
725 async->bio_offset);
726 }
727
728 static void run_one_async_done(struct btrfs_work *work)
729 {
730 struct btrfs_fs_info *fs_info;
731 struct async_submit_bio *async;
732 int limit;
733
734 async = container_of(work, struct async_submit_bio, work);
735 fs_info = BTRFS_I(async->inode)->root->fs_info;
736
737 limit = btrfs_async_submit_limit(fs_info);
738 limit = limit * 2 / 3;
739
740 atomic_dec(&fs_info->nr_async_submits);
741
742 if (atomic_read(&fs_info->nr_async_submits) < limit &&
743 waitqueue_active(&fs_info->async_submit_wait))
744 wake_up(&fs_info->async_submit_wait);
745
746 async->submit_bio_done(async->inode, async->rw, async->bio,
747 async->mirror_num, async->bio_flags,
748 async->bio_offset);
749 }
750
751 static void run_one_async_free(struct btrfs_work *work)
752 {
753 struct async_submit_bio *async;
754
755 async = container_of(work, struct async_submit_bio, work);
756 kfree(async);
757 }
758
759 int btrfs_wq_submit_bio(struct btrfs_fs_info *fs_info, struct inode *inode,
760 int rw, struct bio *bio, int mirror_num,
761 unsigned long bio_flags,
762 u64 bio_offset,
763 extent_submit_bio_hook_t *submit_bio_start,
764 extent_submit_bio_hook_t *submit_bio_done)
765 {
766 struct async_submit_bio *async;
767
768 async = kmalloc(sizeof(*async), GFP_NOFS);
769 if (!async)
770 return -ENOMEM;
771
772 async->inode = inode;
773 async->rw = rw;
774 async->bio = bio;
775 async->mirror_num = mirror_num;
776 async->submit_bio_start = submit_bio_start;
777 async->submit_bio_done = submit_bio_done;
778
779 async->work.func = run_one_async_start;
780 async->work.ordered_func = run_one_async_done;
781 async->work.ordered_free = run_one_async_free;
782
783 async->work.flags = 0;
784 async->bio_flags = bio_flags;
785 async->bio_offset = bio_offset;
786
787 atomic_inc(&fs_info->nr_async_submits);
788
789 if (rw & REQ_SYNC)
790 btrfs_set_work_high_prio(&async->work);
791
792 btrfs_queue_worker(&fs_info->workers, &async->work);
793
794 while (atomic_read(&fs_info->async_submit_draining) &&
795 atomic_read(&fs_info->nr_async_submits)) {
796 wait_event(fs_info->async_submit_wait,
797 (atomic_read(&fs_info->nr_async_submits) == 0));
798 }
799
800 return 0;
801 }
802
803 static int btree_csum_one_bio(struct bio *bio)
804 {
805 struct bio_vec *bvec = bio->bi_io_vec;
806 int bio_index = 0;
807 struct btrfs_root *root;
808
809 WARN_ON(bio->bi_vcnt <= 0);
810 while (bio_index < bio->bi_vcnt) {
811 root = BTRFS_I(bvec->bv_page->mapping->host)->root;
812 csum_dirty_buffer(root, bvec->bv_page);
813 bio_index++;
814 bvec++;
815 }
816 return 0;
817 }
818
819 static int __btree_submit_bio_start(struct inode *inode, int rw,
820 struct bio *bio, int mirror_num,
821 unsigned long bio_flags,
822 u64 bio_offset)
823 {
824 /*
825 * when we're called for a write, we're already in the async
826 * submission context. Just jump into btrfs_map_bio
827 */
828 btree_csum_one_bio(bio);
829 return 0;
830 }
831
832 static int __btree_submit_bio_done(struct inode *inode, int rw, struct bio *bio,
833 int mirror_num, unsigned long bio_flags,
834 u64 bio_offset)
835 {
836 /*
837 * when we're called for a write, we're already in the async
838 * submission context. Just jump into btrfs_map_bio
839 */
840 return btrfs_map_bio(BTRFS_I(inode)->root, rw, bio, mirror_num, 1);
841 }
842
843 static int btree_submit_bio_hook(struct inode *inode, int rw, struct bio *bio,
844 int mirror_num, unsigned long bio_flags,
845 u64 bio_offset)
846 {
847 int ret;
848
849 ret = btrfs_bio_wq_end_io(BTRFS_I(inode)->root->fs_info,
850 bio, 1);
851 BUG_ON(ret);
852
853 if (!(rw & REQ_WRITE)) {
854 /*
855 * called for a read, do the setup so that checksum validation
856 * can happen in the async kernel threads
857 */
858 return btrfs_map_bio(BTRFS_I(inode)->root, rw, bio,
859 mirror_num, 0);
860 }
861
862 /*
863 * kthread helpers are used to submit writes so that checksumming
864 * can happen in parallel across all CPUs
865 */
866 return btrfs_wq_submit_bio(BTRFS_I(inode)->root->fs_info,
867 inode, rw, bio, mirror_num, 0,
868 bio_offset,
869 __btree_submit_bio_start,
870 __btree_submit_bio_done);
871 }
872
873 #ifdef CONFIG_MIGRATION
874 static int btree_migratepage(struct address_space *mapping,
875 struct page *newpage, struct page *page)
876 {
877 /*
878 * we can't safely write a btree page from here,
879 * we haven't done the locking hook
880 */
881 if (PageDirty(page))
882 return -EAGAIN;
883 /*
884 * Buffers may be managed in a filesystem specific way.
885 * We must have no buffers or drop them.
886 */
887 if (page_has_private(page) &&
888 !try_to_release_page(page, GFP_KERNEL))
889 return -EAGAIN;
890 return migrate_page(mapping, newpage, page);
891 }
892 #endif
893
894 static int btree_writepage(struct page *page, struct writeback_control *wbc)
895 {
896 struct extent_io_tree *tree;
897 struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
898 struct extent_buffer *eb;
899 int was_dirty;
900
901 tree = &BTRFS_I(page->mapping->host)->io_tree;
902 if (!(current->flags & PF_MEMALLOC)) {
903 return extent_write_full_page(tree, page,
904 btree_get_extent, wbc);
905 }
906
907 redirty_page_for_writepage(wbc, page);
908 eb = btrfs_find_tree_block(root, page_offset(page), PAGE_CACHE_SIZE);
909 WARN_ON(!eb);
910
911 was_dirty = test_and_set_bit(EXTENT_BUFFER_DIRTY, &eb->bflags);
912 if (!was_dirty) {
913 spin_lock(&root->fs_info->delalloc_lock);
914 root->fs_info->dirty_metadata_bytes += PAGE_CACHE_SIZE;
915 spin_unlock(&root->fs_info->delalloc_lock);
916 }
917 free_extent_buffer(eb);
918
919 unlock_page(page);
920 return 0;
921 }
922
923 static int btree_writepages(struct address_space *mapping,
924 struct writeback_control *wbc)
925 {
926 struct extent_io_tree *tree;
927 tree = &BTRFS_I(mapping->host)->io_tree;
928 if (wbc->sync_mode == WB_SYNC_NONE) {
929 struct btrfs_root *root = BTRFS_I(mapping->host)->root;
930 u64 num_dirty;
931 unsigned long thresh = 32 * 1024 * 1024;
932
933 if (wbc->for_kupdate)
934 return 0;
935
936 /* this is a bit racy, but that's ok */
937 num_dirty = root->fs_info->dirty_metadata_bytes;
938 if (num_dirty < thresh)
939 return 0;
940 }
941 return extent_writepages(tree, mapping, btree_get_extent, wbc);
942 }
943
944 static int btree_readpage(struct file *file, struct page *page)
945 {
946 struct extent_io_tree *tree;
947 tree = &BTRFS_I(page->mapping->host)->io_tree;
948 return extent_read_full_page(tree, page, btree_get_extent, 0);
949 }
950
951 static int btree_releasepage(struct page *page, gfp_t gfp_flags)
952 {
953 struct extent_io_tree *tree;
954 struct extent_map_tree *map;
955 int ret;
956
957 if (PageWriteback(page) || PageDirty(page))
958 return 0;
959
960 tree = &BTRFS_I(page->mapping->host)->io_tree;
961 map = &BTRFS_I(page->mapping->host)->extent_tree;
962
963 ret = try_release_extent_state(map, tree, page, gfp_flags);
964 if (!ret)
965 return 0;
966
967 ret = try_release_extent_buffer(tree, page);
968 if (ret == 1) {
969 ClearPagePrivate(page);
970 set_page_private(page, 0);
971 page_cache_release(page);
972 }
973
974 return ret;
975 }
976
977 static void btree_invalidatepage(struct page *page, unsigned long offset)
978 {
979 struct extent_io_tree *tree;
980 tree = &BTRFS_I(page->mapping->host)->io_tree;
981 extent_invalidatepage(tree, page, offset);
982 btree_releasepage(page, GFP_NOFS);
983 if (PagePrivate(page)) {
984 printk(KERN_WARNING "btrfs warning page private not zero "
985 "on page %llu\n", (unsigned long long)page_offset(page));
986 ClearPagePrivate(page);
987 set_page_private(page, 0);
988 page_cache_release(page);
989 }
990 }
991
992 static const struct address_space_operations btree_aops = {
993 .readpage = btree_readpage,
994 .writepage = btree_writepage,
995 .writepages = btree_writepages,
996 .releasepage = btree_releasepage,
997 .invalidatepage = btree_invalidatepage,
998 #ifdef CONFIG_MIGRATION
999 .migratepage = btree_migratepage,
1000 #endif
1001 };
1002
1003 int readahead_tree_block(struct btrfs_root *root, u64 bytenr, u32 blocksize,
1004 u64 parent_transid)
1005 {
1006 struct extent_buffer *buf = NULL;
1007 struct inode *btree_inode = root->fs_info->btree_inode;
1008 int ret = 0;
1009
1010 buf = btrfs_find_create_tree_block(root, bytenr, blocksize);
1011 if (!buf)
1012 return 0;
1013 read_extent_buffer_pages(&BTRFS_I(btree_inode)->io_tree,
1014 buf, 0, WAIT_NONE, btree_get_extent, 0);
1015 free_extent_buffer(buf);
1016 return ret;
1017 }
1018
1019 int reada_tree_block_flagged(struct btrfs_root *root, u64 bytenr, u32 blocksize,
1020 int mirror_num, struct extent_buffer **eb)
1021 {
1022 struct extent_buffer *buf = NULL;
1023 struct inode *btree_inode = root->fs_info->btree_inode;
1024 struct extent_io_tree *io_tree = &BTRFS_I(btree_inode)->io_tree;
1025 int ret;
1026
1027 buf = btrfs_find_create_tree_block(root, bytenr, blocksize);
1028 if (!buf)
1029 return 0;
1030
1031 set_bit(EXTENT_BUFFER_READAHEAD, &buf->bflags);
1032
1033 ret = read_extent_buffer_pages(io_tree, buf, 0, WAIT_PAGE_LOCK,
1034 btree_get_extent, mirror_num);
1035 if (ret) {
1036 free_extent_buffer(buf);
1037 return ret;
1038 }
1039
1040 if (test_bit(EXTENT_BUFFER_CORRUPT, &buf->bflags)) {
1041 free_extent_buffer(buf);
1042 return -EIO;
1043 } else if (extent_buffer_uptodate(io_tree, buf, NULL)) {
1044 *eb = buf;
1045 } else {
1046 free_extent_buffer(buf);
1047 }
1048 return 0;
1049 }
1050
1051 struct extent_buffer *btrfs_find_tree_block(struct btrfs_root *root,
1052 u64 bytenr, u32 blocksize)
1053 {
1054 struct inode *btree_inode = root->fs_info->btree_inode;
1055 struct extent_buffer *eb;
1056 eb = find_extent_buffer(&BTRFS_I(btree_inode)->io_tree,
1057 bytenr, blocksize);
1058 return eb;
1059 }
1060
1061 struct extent_buffer *btrfs_find_create_tree_block(struct btrfs_root *root,
1062 u64 bytenr, u32 blocksize)
1063 {
1064 struct inode *btree_inode = root->fs_info->btree_inode;
1065 struct extent_buffer *eb;
1066
1067 eb = alloc_extent_buffer(&BTRFS_I(btree_inode)->io_tree,
1068 bytenr, blocksize, NULL);
1069 return eb;
1070 }
1071
1072
1073 int btrfs_write_tree_block(struct extent_buffer *buf)
1074 {
1075 return filemap_fdatawrite_range(buf->first_page->mapping, buf->start,
1076 buf->start + buf->len - 1);
1077 }
1078
1079 int btrfs_wait_tree_block_writeback(struct extent_buffer *buf)
1080 {
1081 return filemap_fdatawait_range(buf->first_page->mapping,
1082 buf->start, buf->start + buf->len - 1);
1083 }
1084
1085 struct extent_buffer *read_tree_block(struct btrfs_root *root, u64 bytenr,
1086 u32 blocksize, u64 parent_transid)
1087 {
1088 struct extent_buffer *buf = NULL;
1089 int ret;
1090
1091 buf = btrfs_find_create_tree_block(root, bytenr, blocksize);
1092 if (!buf)
1093 return NULL;
1094
1095 ret = btree_read_extent_buffer_pages(root, buf, 0, parent_transid);
1096
1097 if (ret == 0)
1098 set_bit(EXTENT_BUFFER_UPTODATE, &buf->bflags);
1099 return buf;
1100
1101 }
1102
1103 int clean_tree_block(struct btrfs_trans_handle *trans, struct btrfs_root *root,
1104 struct extent_buffer *buf)
1105 {
1106 struct inode *btree_inode = root->fs_info->btree_inode;
1107 if (btrfs_header_generation(buf) ==
1108 root->fs_info->running_transaction->transid) {
1109 btrfs_assert_tree_locked(buf);
1110
1111 if (test_and_clear_bit(EXTENT_BUFFER_DIRTY, &buf->bflags)) {
1112 spin_lock(&root->fs_info->delalloc_lock);
1113 if (root->fs_info->dirty_metadata_bytes >= buf->len)
1114 root->fs_info->dirty_metadata_bytes -= buf->len;
1115 else
1116 WARN_ON(1);
1117 spin_unlock(&root->fs_info->delalloc_lock);
1118 }
1119
1120 /* ugh, clear_extent_buffer_dirty needs to lock the page */
1121 btrfs_set_lock_blocking(buf);
1122 clear_extent_buffer_dirty(&BTRFS_I(btree_inode)->io_tree,
1123 buf);
1124 }
1125 return 0;
1126 }
1127
1128 static int __setup_root(u32 nodesize, u32 leafsize, u32 sectorsize,
1129 u32 stripesize, struct btrfs_root *root,
1130 struct btrfs_fs_info *fs_info,
1131 u64 objectid)
1132 {
1133 root->node = NULL;
1134 root->commit_root = NULL;
1135 root->sectorsize = sectorsize;
1136 root->nodesize = nodesize;
1137 root->leafsize = leafsize;
1138 root->stripesize = stripesize;
1139 root->ref_cows = 0;
1140 root->track_dirty = 0;
1141 root->in_radix = 0;
1142 root->orphan_item_inserted = 0;
1143 root->orphan_cleanup_state = 0;
1144
1145 root->fs_info = fs_info;
1146 root->objectid = objectid;
1147 root->last_trans = 0;
1148 root->highest_objectid = 0;
1149 root->name = NULL;
1150 root->inode_tree = RB_ROOT;
1151 INIT_RADIX_TREE(&root->delayed_nodes_tree, GFP_ATOMIC);
1152 root->block_rsv = NULL;
1153 root->orphan_block_rsv = NULL;
1154
1155 INIT_LIST_HEAD(&root->dirty_list);
1156 INIT_LIST_HEAD(&root->orphan_list);
1157 INIT_LIST_HEAD(&root->root_list);
1158 spin_lock_init(&root->orphan_lock);
1159 spin_lock_init(&root->inode_lock);
1160 spin_lock_init(&root->accounting_lock);
1161 mutex_init(&root->objectid_mutex);
1162 mutex_init(&root->log_mutex);
1163 init_waitqueue_head(&root->log_writer_wait);
1164 init_waitqueue_head(&root->log_commit_wait[0]);
1165 init_waitqueue_head(&root->log_commit_wait[1]);
1166 atomic_set(&root->log_commit[0], 0);
1167 atomic_set(&root->log_commit[1], 0);
1168 atomic_set(&root->log_writers, 0);
1169 root->log_batch = 0;
1170 root->log_transid = 0;
1171 root->last_log_commit = 0;
1172 extent_io_tree_init(&root->dirty_log_pages,
1173 fs_info->btree_inode->i_mapping);
1174
1175 memset(&root->root_key, 0, sizeof(root->root_key));
1176 memset(&root->root_item, 0, sizeof(root->root_item));
1177 memset(&root->defrag_progress, 0, sizeof(root->defrag_progress));
1178 memset(&root->root_kobj, 0, sizeof(root->root_kobj));
1179 root->defrag_trans_start = fs_info->generation;
1180 init_completion(&root->kobj_unregister);
1181 root->defrag_running = 0;
1182 root->root_key.objectid = objectid;
1183 root->anon_dev = 0;
1184 return 0;
1185 }
1186
1187 static int find_and_setup_root(struct btrfs_root *tree_root,
1188 struct btrfs_fs_info *fs_info,
1189 u64 objectid,
1190 struct btrfs_root *root)
1191 {
1192 int ret;
1193 u32 blocksize;
1194 u64 generation;
1195
1196 __setup_root(tree_root->nodesize, tree_root->leafsize,
1197 tree_root->sectorsize, tree_root->stripesize,
1198 root, fs_info, objectid);
1199 ret = btrfs_find_last_root(tree_root, objectid,
1200 &root->root_item, &root->root_key);
1201 if (ret > 0)
1202 return -ENOENT;
1203 BUG_ON(ret);
1204
1205 generation = btrfs_root_generation(&root->root_item);
1206 blocksize = btrfs_level_size(root, btrfs_root_level(&root->root_item));
1207 root->commit_root = NULL;
1208 root->node = read_tree_block(root, btrfs_root_bytenr(&root->root_item),
1209 blocksize, generation);
1210 if (!root->node || !btrfs_buffer_uptodate(root->node, generation)) {
1211 free_extent_buffer(root->node);
1212 root->node = NULL;
1213 return -EIO;
1214 }
1215 root->commit_root = btrfs_root_node(root);
1216 return 0;
1217 }
1218
1219 static struct btrfs_root *alloc_log_tree(struct btrfs_trans_handle *trans,
1220 struct btrfs_fs_info *fs_info)
1221 {
1222 struct btrfs_root *root;
1223 struct btrfs_root *tree_root = fs_info->tree_root;
1224 struct extent_buffer *leaf;
1225
1226 root = kzalloc(sizeof(*root), GFP_NOFS);
1227 if (!root)
1228 return ERR_PTR(-ENOMEM);
1229
1230 __setup_root(tree_root->nodesize, tree_root->leafsize,
1231 tree_root->sectorsize, tree_root->stripesize,
1232 root, fs_info, BTRFS_TREE_LOG_OBJECTID);
1233
1234 root->root_key.objectid = BTRFS_TREE_LOG_OBJECTID;
1235 root->root_key.type = BTRFS_ROOT_ITEM_KEY;
1236 root->root_key.offset = BTRFS_TREE_LOG_OBJECTID;
1237 /*
1238 * log trees do not get reference counted because they go away
1239 * before a real commit is actually done. They do store pointers
1240 * to file data extents, and those reference counts still get
1241 * updated (along with back refs to the log tree).
1242 */
1243 root->ref_cows = 0;
1244
1245 leaf = btrfs_alloc_free_block(trans, root, root->leafsize, 0,
1246 BTRFS_TREE_LOG_OBJECTID, NULL, 0, 0, 0);
1247 if (IS_ERR(leaf)) {
1248 kfree(root);
1249 return ERR_CAST(leaf);
1250 }
1251
1252 memset_extent_buffer(leaf, 0, 0, sizeof(struct btrfs_header));
1253 btrfs_set_header_bytenr(leaf, leaf->start);
1254 btrfs_set_header_generation(leaf, trans->transid);
1255 btrfs_set_header_backref_rev(leaf, BTRFS_MIXED_BACKREF_REV);
1256 btrfs_set_header_owner(leaf, BTRFS_TREE_LOG_OBJECTID);
1257 root->node = leaf;
1258
1259 write_extent_buffer(root->node, root->fs_info->fsid,
1260 (unsigned long)btrfs_header_fsid(root->node),
1261 BTRFS_FSID_SIZE);
1262 btrfs_mark_buffer_dirty(root->node);
1263 btrfs_tree_unlock(root->node);
1264 return root;
1265 }
1266
1267 int btrfs_init_log_root_tree(struct btrfs_trans_handle *trans,
1268 struct btrfs_fs_info *fs_info)
1269 {
1270 struct btrfs_root *log_root;
1271
1272 log_root = alloc_log_tree(trans, fs_info);
1273 if (IS_ERR(log_root))
1274 return PTR_ERR(log_root);
1275 WARN_ON(fs_info->log_root_tree);
1276 fs_info->log_root_tree = log_root;
1277 return 0;
1278 }
1279
1280 int btrfs_add_log_tree(struct btrfs_trans_handle *trans,
1281 struct btrfs_root *root)
1282 {
1283 struct btrfs_root *log_root;
1284 struct btrfs_inode_item *inode_item;
1285
1286 log_root = alloc_log_tree(trans, root->fs_info);
1287 if (IS_ERR(log_root))
1288 return PTR_ERR(log_root);
1289
1290 log_root->last_trans = trans->transid;
1291 log_root->root_key.offset = root->root_key.objectid;
1292
1293 inode_item = &log_root->root_item.inode;
1294 inode_item->generation = cpu_to_le64(1);
1295 inode_item->size = cpu_to_le64(3);
1296 inode_item->nlink = cpu_to_le32(1);
1297 inode_item->nbytes = cpu_to_le64(root->leafsize);
1298 inode_item->mode = cpu_to_le32(S_IFDIR | 0755);
1299
1300 btrfs_set_root_node(&log_root->root_item, log_root->node);
1301
1302 WARN_ON(root->log_root);
1303 root->log_root = log_root;
1304 root->log_transid = 0;
1305 root->last_log_commit = 0;
1306 return 0;
1307 }
1308
1309 struct btrfs_root *btrfs_read_fs_root_no_radix(struct btrfs_root *tree_root,
1310 struct btrfs_key *location)
1311 {
1312 struct btrfs_root *root;
1313 struct btrfs_fs_info *fs_info = tree_root->fs_info;
1314 struct btrfs_path *path;
1315 struct extent_buffer *l;
1316 u64 generation;
1317 u32 blocksize;
1318 int ret = 0;
1319
1320 root = kzalloc(sizeof(*root), GFP_NOFS);
1321 if (!root)
1322 return ERR_PTR(-ENOMEM);
1323 if (location->offset == (u64)-1) {
1324 ret = find_and_setup_root(tree_root, fs_info,
1325 location->objectid, root);
1326 if (ret) {
1327 kfree(root);
1328 return ERR_PTR(ret);
1329 }
1330 goto out;
1331 }
1332
1333 __setup_root(tree_root->nodesize, tree_root->leafsize,
1334 tree_root->sectorsize, tree_root->stripesize,
1335 root, fs_info, location->objectid);
1336
1337 path = btrfs_alloc_path();
1338 if (!path) {
1339 kfree(root);
1340 return ERR_PTR(-ENOMEM);
1341 }
1342 ret = btrfs_search_slot(NULL, tree_root, location, path, 0, 0);
1343 if (ret == 0) {
1344 l = path->nodes[0];
1345 read_extent_buffer(l, &root->root_item,
1346 btrfs_item_ptr_offset(l, path->slots[0]),
1347 sizeof(root->root_item));
1348 memcpy(&root->root_key, location, sizeof(*location));
1349 }
1350 btrfs_free_path(path);
1351 if (ret) {
1352 kfree(root);
1353 if (ret > 0)
1354 ret = -ENOENT;
1355 return ERR_PTR(ret);
1356 }
1357
1358 generation = btrfs_root_generation(&root->root_item);
1359 blocksize = btrfs_level_size(root, btrfs_root_level(&root->root_item));
1360 root->node = read_tree_block(root, btrfs_root_bytenr(&root->root_item),
1361 blocksize, generation);
1362 root->commit_root = btrfs_root_node(root);
1363 BUG_ON(!root->node);
1364 out:
1365 if (location->objectid != BTRFS_TREE_LOG_OBJECTID) {
1366 root->ref_cows = 1;
1367 btrfs_check_and_init_root_item(&root->root_item);
1368 }
1369
1370 return root;
1371 }
1372
1373 struct btrfs_root *btrfs_read_fs_root_no_name(struct btrfs_fs_info *fs_info,
1374 struct btrfs_key *location)
1375 {
1376 struct btrfs_root *root;
1377 int ret;
1378
1379 if (location->objectid == BTRFS_ROOT_TREE_OBJECTID)
1380 return fs_info->tree_root;
1381 if (location->objectid == BTRFS_EXTENT_TREE_OBJECTID)
1382 return fs_info->extent_root;
1383 if (location->objectid == BTRFS_CHUNK_TREE_OBJECTID)
1384 return fs_info->chunk_root;
1385 if (location->objectid == BTRFS_DEV_TREE_OBJECTID)
1386 return fs_info->dev_root;
1387 if (location->objectid == BTRFS_CSUM_TREE_OBJECTID)
1388 return fs_info->csum_root;
1389 again:
1390 spin_lock(&fs_info->fs_roots_radix_lock);
1391 root = radix_tree_lookup(&fs_info->fs_roots_radix,
1392 (unsigned long)location->objectid);
1393 spin_unlock(&fs_info->fs_roots_radix_lock);
1394 if (root)
1395 return root;
1396
1397 root = btrfs_read_fs_root_no_radix(fs_info->tree_root, location);
1398 if (IS_ERR(root))
1399 return root;
1400
1401 root->free_ino_ctl = kzalloc(sizeof(*root->free_ino_ctl), GFP_NOFS);
1402 root->free_ino_pinned = kzalloc(sizeof(*root->free_ino_pinned),
1403 GFP_NOFS);
1404 if (!root->free_ino_pinned || !root->free_ino_ctl) {
1405 ret = -ENOMEM;
1406 goto fail;
1407 }
1408
1409 btrfs_init_free_ino_ctl(root);
1410 mutex_init(&root->fs_commit_mutex);
1411 spin_lock_init(&root->cache_lock);
1412 init_waitqueue_head(&root->cache_wait);
1413
1414 ret = get_anon_bdev(&root->anon_dev);
1415 if (ret)
1416 goto fail;
1417
1418 if (btrfs_root_refs(&root->root_item) == 0) {
1419 ret = -ENOENT;
1420 goto fail;
1421 }
1422
1423 ret = btrfs_find_orphan_item(fs_info->tree_root, location->objectid);
1424 if (ret < 0)
1425 goto fail;
1426 if (ret == 0)
1427 root->orphan_item_inserted = 1;
1428
1429 ret = radix_tree_preload(GFP_NOFS & ~__GFP_HIGHMEM);
1430 if (ret)
1431 goto fail;
1432
1433 spin_lock(&fs_info->fs_roots_radix_lock);
1434 ret = radix_tree_insert(&fs_info->fs_roots_radix,
1435 (unsigned long)root->root_key.objectid,
1436 root);
1437 if (ret == 0)
1438 root->in_radix = 1;
1439
1440 spin_unlock(&fs_info->fs_roots_radix_lock);
1441 radix_tree_preload_end();
1442 if (ret) {
1443 if (ret == -EEXIST) {
1444 free_fs_root(root);
1445 goto again;
1446 }
1447 goto fail;
1448 }
1449
1450 ret = btrfs_find_dead_roots(fs_info->tree_root,
1451 root->root_key.objectid);
1452 WARN_ON(ret);
1453 return root;
1454 fail:
1455 free_fs_root(root);
1456 return ERR_PTR(ret);
1457 }
1458
1459 static int btrfs_congested_fn(void *congested_data, int bdi_bits)
1460 {
1461 struct btrfs_fs_info *info = (struct btrfs_fs_info *)congested_data;
1462 int ret = 0;
1463 struct btrfs_device *device;
1464 struct backing_dev_info *bdi;
1465
1466 rcu_read_lock();
1467 list_for_each_entry_rcu(device, &info->fs_devices->devices, dev_list) {
1468 if (!device->bdev)
1469 continue;
1470 bdi = blk_get_backing_dev_info(device->bdev);
1471 if (bdi && bdi_congested(bdi, bdi_bits)) {
1472 ret = 1;
1473 break;
1474 }
1475 }
1476 rcu_read_unlock();
1477 return ret;
1478 }
1479
1480 /*
1481 * If this fails, caller must call bdi_destroy() to get rid of the
1482 * bdi again.
1483 */
1484 static int setup_bdi(struct btrfs_fs_info *info, struct backing_dev_info *bdi)
1485 {
1486 int err;
1487
1488 bdi->capabilities = BDI_CAP_MAP_COPY;
1489 err = bdi_setup_and_register(bdi, "btrfs", BDI_CAP_MAP_COPY);
1490 if (err)
1491 return err;
1492
1493 bdi->ra_pages = default_backing_dev_info.ra_pages;
1494 bdi->congested_fn = btrfs_congested_fn;
1495 bdi->congested_data = info;
1496 return 0;
1497 }
1498
1499 static int bio_ready_for_csum(struct bio *bio)
1500 {
1501 u64 length = 0;
1502 u64 buf_len = 0;
1503 u64 start = 0;
1504 struct page *page;
1505 struct extent_io_tree *io_tree = NULL;
1506 struct bio_vec *bvec;
1507 int i;
1508 int ret;
1509
1510 bio_for_each_segment(bvec, bio, i) {
1511 page = bvec->bv_page;
1512 if (page->private == EXTENT_PAGE_PRIVATE) {
1513 length += bvec->bv_len;
1514 continue;
1515 }
1516 if (!page->private) {
1517 length += bvec->bv_len;
1518 continue;
1519 }
1520 length = bvec->bv_len;
1521 buf_len = page->private >> 2;
1522 start = page_offset(page) + bvec->bv_offset;
1523 io_tree = &BTRFS_I(page->mapping->host)->io_tree;
1524 }
1525 /* are we fully contained in this bio? */
1526 if (buf_len <= length)
1527 return 1;
1528
1529 ret = extent_range_uptodate(io_tree, start + length,
1530 start + buf_len - 1);
1531 return ret;
1532 }
1533
1534 /*
1535 * called by the kthread helper functions to finally call the bio end_io
1536 * functions. This is where read checksum verification actually happens
1537 */
1538 static void end_workqueue_fn(struct btrfs_work *work)
1539 {
1540 struct bio *bio;
1541 struct end_io_wq *end_io_wq;
1542 struct btrfs_fs_info *fs_info;
1543 int error;
1544
1545 end_io_wq = container_of(work, struct end_io_wq, work);
1546 bio = end_io_wq->bio;
1547 fs_info = end_io_wq->info;
1548
1549 /* metadata bio reads are special because the whole tree block must
1550 * be checksummed at once. This makes sure the entire block is in
1551 * ram and up to date before trying to verify things. For
1552 * blocksize <= pagesize, it is basically a noop
1553 */
1554 if (!(bio->bi_rw & REQ_WRITE) && end_io_wq->metadata &&
1555 !bio_ready_for_csum(bio)) {
1556 btrfs_queue_worker(&fs_info->endio_meta_workers,
1557 &end_io_wq->work);
1558 return;
1559 }
1560 error = end_io_wq->error;
1561 bio->bi_private = end_io_wq->private;
1562 bio->bi_end_io = end_io_wq->end_io;
1563 kfree(end_io_wq);
1564 bio_endio(bio, error);
1565 }
1566
1567 static int cleaner_kthread(void *arg)
1568 {
1569 struct btrfs_root *root = arg;
1570
1571 do {
1572 vfs_check_frozen(root->fs_info->sb, SB_FREEZE_WRITE);
1573
1574 if (!(root->fs_info->sb->s_flags & MS_RDONLY) &&
1575 mutex_trylock(&root->fs_info->cleaner_mutex)) {
1576 btrfs_run_delayed_iputs(root);
1577 btrfs_clean_old_snapshots(root);
1578 mutex_unlock(&root->fs_info->cleaner_mutex);
1579 btrfs_run_defrag_inodes(root->fs_info);
1580 }
1581
1582 if (freezing(current)) {
1583 refrigerator();
1584 } else {
1585 set_current_state(TASK_INTERRUPTIBLE);
1586 if (!kthread_should_stop())
1587 schedule();
1588 __set_current_state(TASK_RUNNING);
1589 }
1590 } while (!kthread_should_stop());
1591 return 0;
1592 }
1593
1594 static int transaction_kthread(void *arg)
1595 {
1596 struct btrfs_root *root = arg;
1597 struct btrfs_trans_handle *trans;
1598 struct btrfs_transaction *cur;
1599 u64 transid;
1600 unsigned long now;
1601 unsigned long delay;
1602 int ret;
1603
1604 do {
1605 delay = HZ * 30;
1606 vfs_check_frozen(root->fs_info->sb, SB_FREEZE_WRITE);
1607 mutex_lock(&root->fs_info->transaction_kthread_mutex);
1608
1609 spin_lock(&root->fs_info->trans_lock);
1610 cur = root->fs_info->running_transaction;
1611 if (!cur) {
1612 spin_unlock(&root->fs_info->trans_lock);
1613 goto sleep;
1614 }
1615
1616 now = get_seconds();
1617 if (!cur->blocked &&
1618 (now < cur->start_time || now - cur->start_time < 30)) {
1619 spin_unlock(&root->fs_info->trans_lock);
1620 delay = HZ * 5;
1621 goto sleep;
1622 }
1623 transid = cur->transid;
1624 spin_unlock(&root->fs_info->trans_lock);
1625
1626 trans = btrfs_join_transaction(root);
1627 BUG_ON(IS_ERR(trans));
1628 if (transid == trans->transid) {
1629 ret = btrfs_commit_transaction(trans, root);
1630 BUG_ON(ret);
1631 } else {
1632 btrfs_end_transaction(trans, root);
1633 }
1634 sleep:
1635 wake_up_process(root->fs_info->cleaner_kthread);
1636 mutex_unlock(&root->fs_info->transaction_kthread_mutex);
1637
1638 if (freezing(current)) {
1639 refrigerator();
1640 } else {
1641 set_current_state(TASK_INTERRUPTIBLE);
1642 if (!kthread_should_stop() &&
1643 !btrfs_transaction_blocked(root->fs_info))
1644 schedule_timeout(delay);
1645 __set_current_state(TASK_RUNNING);
1646 }
1647 } while (!kthread_should_stop());
1648 return 0;
1649 }
1650
1651 /*
1652 * this will find the highest generation in the array of
1653 * root backups. The index of the highest array is returned,
1654 * or -1 if we can't find anything.
1655 *
1656 * We check to make sure the array is valid by comparing the
1657 * generation of the latest root in the array with the generation
1658 * in the super block. If they don't match we pitch it.
1659 */
1660 static int find_newest_super_backup(struct btrfs_fs_info *info, u64 newest_gen)
1661 {
1662 u64 cur;
1663 int newest_index = -1;
1664 struct btrfs_root_backup *root_backup;
1665 int i;
1666
1667 for (i = 0; i < BTRFS_NUM_BACKUP_ROOTS; i++) {
1668 root_backup = info->super_copy->super_roots + i;
1669 cur = btrfs_backup_tree_root_gen(root_backup);
1670 if (cur == newest_gen)
1671 newest_index = i;
1672 }
1673
1674 /* check to see if we actually wrapped around */
1675 if (newest_index == BTRFS_NUM_BACKUP_ROOTS - 1) {
1676 root_backup = info->super_copy->super_roots;
1677 cur = btrfs_backup_tree_root_gen(root_backup);
1678 if (cur == newest_gen)
1679 newest_index = 0;
1680 }
1681 return newest_index;
1682 }
1683
1684
1685 /*
1686 * find the oldest backup so we know where to store new entries
1687 * in the backup array. This will set the backup_root_index
1688 * field in the fs_info struct
1689 */
1690 static void find_oldest_super_backup(struct btrfs_fs_info *info,
1691 u64 newest_gen)
1692 {
1693 int newest_index = -1;
1694
1695 newest_index = find_newest_super_backup(info, newest_gen);
1696 /* if there was garbage in there, just move along */
1697 if (newest_index == -1) {
1698 info->backup_root_index = 0;
1699 } else {
1700 info->backup_root_index = (newest_index + 1) % BTRFS_NUM_BACKUP_ROOTS;
1701 }
1702 }
1703
1704 /*
1705 * copy all the root pointers into the super backup array.
1706 * this will bump the backup pointer by one when it is
1707 * done
1708 */
1709 static void backup_super_roots(struct btrfs_fs_info *info)
1710 {
1711 int next_backup;
1712 struct btrfs_root_backup *root_backup;
1713 int last_backup;
1714
1715 next_backup = info->backup_root_index;
1716 last_backup = (next_backup + BTRFS_NUM_BACKUP_ROOTS - 1) %
1717 BTRFS_NUM_BACKUP_ROOTS;
1718
1719 /*
1720 * just overwrite the last backup if we're at the same generation
1721 * this happens only at umount
1722 */
1723 root_backup = info->super_for_commit->super_roots + last_backup;
1724 if (btrfs_backup_tree_root_gen(root_backup) ==
1725 btrfs_header_generation(info->tree_root->node))
1726 next_backup = last_backup;
1727
1728 root_backup = info->super_for_commit->super_roots + next_backup;
1729
1730 /*
1731 * make sure all of our padding and empty slots get zero filled
1732 * regardless of which ones we use today
1733 */
1734 memset(root_backup, 0, sizeof(*root_backup));
1735
1736 info->backup_root_index = (next_backup + 1) % BTRFS_NUM_BACKUP_ROOTS;
1737
1738 btrfs_set_backup_tree_root(root_backup, info->tree_root->node->start);
1739 btrfs_set_backup_tree_root_gen(root_backup,
1740 btrfs_header_generation(info->tree_root->node));
1741
1742 btrfs_set_backup_tree_root_level(root_backup,
1743 btrfs_header_level(info->tree_root->node));
1744
1745 btrfs_set_backup_chunk_root(root_backup, info->chunk_root->node->start);
1746 btrfs_set_backup_chunk_root_gen(root_backup,
1747 btrfs_header_generation(info->chunk_root->node));
1748 btrfs_set_backup_chunk_root_level(root_backup,
1749 btrfs_header_level(info->chunk_root->node));
1750
1751 btrfs_set_backup_extent_root(root_backup, info->extent_root->node->start);
1752 btrfs_set_backup_extent_root_gen(root_backup,
1753 btrfs_header_generation(info->extent_root->node));
1754 btrfs_set_backup_extent_root_level(root_backup,
1755 btrfs_header_level(info->extent_root->node));
1756
1757 /*
1758 * we might commit during log recovery, which happens before we set
1759 * the fs_root. Make sure it is valid before we fill it in.
1760 */
1761 if (info->fs_root && info->fs_root->node) {
1762 btrfs_set_backup_fs_root(root_backup,
1763 info->fs_root->node->start);
1764 btrfs_set_backup_fs_root_gen(root_backup,
1765 btrfs_header_generation(info->fs_root->node));
1766 btrfs_set_backup_fs_root_level(root_backup,
1767 btrfs_header_level(info->fs_root->node));
1768 }
1769
1770 btrfs_set_backup_dev_root(root_backup, info->dev_root->node->start);
1771 btrfs_set_backup_dev_root_gen(root_backup,
1772 btrfs_header_generation(info->dev_root->node));
1773 btrfs_set_backup_dev_root_level(root_backup,
1774 btrfs_header_level(info->dev_root->node));
1775
1776 btrfs_set_backup_csum_root(root_backup, info->csum_root->node->start);
1777 btrfs_set_backup_csum_root_gen(root_backup,
1778 btrfs_header_generation(info->csum_root->node));
1779 btrfs_set_backup_csum_root_level(root_backup,
1780 btrfs_header_level(info->csum_root->node));
1781
1782 btrfs_set_backup_total_bytes(root_backup,
1783 btrfs_super_total_bytes(info->super_copy));
1784 btrfs_set_backup_bytes_used(root_backup,
1785 btrfs_super_bytes_used(info->super_copy));
1786 btrfs_set_backup_num_devices(root_backup,
1787 btrfs_super_num_devices(info->super_copy));
1788
1789 /*
1790 * if we don't copy this out to the super_copy, it won't get remembered
1791 * for the next commit
1792 */
1793 memcpy(&info->super_copy->super_roots,
1794 &info->super_for_commit->super_roots,
1795 sizeof(*root_backup) * BTRFS_NUM_BACKUP_ROOTS);
1796 }
1797
1798 /*
1799 * this copies info out of the root backup array and back into
1800 * the in-memory super block. It is meant to help iterate through
1801 * the array, so you send it the number of backups you've already
1802 * tried and the last backup index you used.
1803 *
1804 * this returns -1 when it has tried all the backups
1805 */
1806 static noinline int next_root_backup(struct btrfs_fs_info *info,
1807 struct btrfs_super_block *super,
1808 int *num_backups_tried, int *backup_index)
1809 {
1810 struct btrfs_root_backup *root_backup;
1811 int newest = *backup_index;
1812
1813 if (*num_backups_tried == 0) {
1814 u64 gen = btrfs_super_generation(super);
1815
1816 newest = find_newest_super_backup(info, gen);
1817 if (newest == -1)
1818 return -1;
1819
1820 *backup_index = newest;
1821 *num_backups_tried = 1;
1822 } else if (*num_backups_tried == BTRFS_NUM_BACKUP_ROOTS) {
1823 /* we've tried all the backups, all done */
1824 return -1;
1825 } else {
1826 /* jump to the next oldest backup */
1827 newest = (*backup_index + BTRFS_NUM_BACKUP_ROOTS - 1) %
1828 BTRFS_NUM_BACKUP_ROOTS;
1829 *backup_index = newest;
1830 *num_backups_tried += 1;
1831 }
1832 root_backup = super->super_roots + newest;
1833
1834 btrfs_set_super_generation(super,
1835 btrfs_backup_tree_root_gen(root_backup));
1836 btrfs_set_super_root(super, btrfs_backup_tree_root(root_backup));
1837 btrfs_set_super_root_level(super,
1838 btrfs_backup_tree_root_level(root_backup));
1839 btrfs_set_super_bytes_used(super, btrfs_backup_bytes_used(root_backup));
1840
1841 /*
1842 * fixme: the total bytes and num_devices need to match or we should
1843 * need a fsck
1844 */
1845 btrfs_set_super_total_bytes(super, btrfs_backup_total_bytes(root_backup));
1846 btrfs_set_super_num_devices(super, btrfs_backup_num_devices(root_backup));
1847 return 0;
1848 }
1849
1850 /* helper to cleanup tree roots */
1851 static void free_root_pointers(struct btrfs_fs_info *info, int chunk_root)
1852 {
1853 free_extent_buffer(info->tree_root->node);
1854 free_extent_buffer(info->tree_root->commit_root);
1855 free_extent_buffer(info->dev_root->node);
1856 free_extent_buffer(info->dev_root->commit_root);
1857 free_extent_buffer(info->extent_root->node);
1858 free_extent_buffer(info->extent_root->commit_root);
1859 free_extent_buffer(info->csum_root->node);
1860 free_extent_buffer(info->csum_root->commit_root);
1861
1862 info->tree_root->node = NULL;
1863 info->tree_root->commit_root = NULL;
1864 info->dev_root->node = NULL;
1865 info->dev_root->commit_root = NULL;
1866 info->extent_root->node = NULL;
1867 info->extent_root->commit_root = NULL;
1868 info->csum_root->node = NULL;
1869 info->csum_root->commit_root = NULL;
1870
1871 if (chunk_root) {
1872 free_extent_buffer(info->chunk_root->node);
1873 free_extent_buffer(info->chunk_root->commit_root);
1874 info->chunk_root->node = NULL;
1875 info->chunk_root->commit_root = NULL;
1876 }
1877 }
1878
1879
1880 struct btrfs_root *open_ctree(struct super_block *sb,
1881 struct btrfs_fs_devices *fs_devices,
1882 char *options)
1883 {
1884 u32 sectorsize;
1885 u32 nodesize;
1886 u32 leafsize;
1887 u32 blocksize;
1888 u32 stripesize;
1889 u64 generation;
1890 u64 features;
1891 struct btrfs_key location;
1892 struct buffer_head *bh;
1893 struct btrfs_super_block *disk_super;
1894 struct btrfs_root *tree_root = btrfs_sb(sb);
1895 struct btrfs_fs_info *fs_info = tree_root->fs_info;
1896 struct btrfs_root *extent_root;
1897 struct btrfs_root *csum_root;
1898 struct btrfs_root *chunk_root;
1899 struct btrfs_root *dev_root;
1900 struct btrfs_root *log_tree_root;
1901 int ret;
1902 int err = -EINVAL;
1903 int num_backups_tried = 0;
1904 int backup_index = 0;
1905
1906 extent_root = fs_info->extent_root =
1907 kzalloc(sizeof(struct btrfs_root), GFP_NOFS);
1908 csum_root = fs_info->csum_root =
1909 kzalloc(sizeof(struct btrfs_root), GFP_NOFS);
1910 chunk_root = fs_info->chunk_root =
1911 kzalloc(sizeof(struct btrfs_root), GFP_NOFS);
1912 dev_root = fs_info->dev_root =
1913 kzalloc(sizeof(struct btrfs_root), GFP_NOFS);
1914
1915 if (!extent_root || !csum_root || !chunk_root || !dev_root) {
1916 err = -ENOMEM;
1917 goto fail;
1918 }
1919
1920 ret = init_srcu_struct(&fs_info->subvol_srcu);
1921 if (ret) {
1922 err = ret;
1923 goto fail;
1924 }
1925
1926 ret = setup_bdi(fs_info, &fs_info->bdi);
1927 if (ret) {
1928 err = ret;
1929 goto fail_srcu;
1930 }
1931
1932 fs_info->btree_inode = new_inode(sb);
1933 if (!fs_info->btree_inode) {
1934 err = -ENOMEM;
1935 goto fail_bdi;
1936 }
1937
1938 mapping_set_gfp_mask(fs_info->btree_inode->i_mapping, GFP_NOFS);
1939
1940 INIT_RADIX_TREE(&fs_info->fs_roots_radix, GFP_ATOMIC);
1941 INIT_LIST_HEAD(&fs_info->trans_list);
1942 INIT_LIST_HEAD(&fs_info->dead_roots);
1943 INIT_LIST_HEAD(&fs_info->delayed_iputs);
1944 INIT_LIST_HEAD(&fs_info->hashers);
1945 INIT_LIST_HEAD(&fs_info->delalloc_inodes);
1946 INIT_LIST_HEAD(&fs_info->ordered_operations);
1947 INIT_LIST_HEAD(&fs_info->caching_block_groups);
1948 spin_lock_init(&fs_info->delalloc_lock);
1949 spin_lock_init(&fs_info->trans_lock);
1950 spin_lock_init(&fs_info->ref_cache_lock);
1951 spin_lock_init(&fs_info->fs_roots_radix_lock);
1952 spin_lock_init(&fs_info->delayed_iput_lock);
1953 spin_lock_init(&fs_info->defrag_inodes_lock);
1954 spin_lock_init(&fs_info->free_chunk_lock);
1955 mutex_init(&fs_info->reloc_mutex);
1956
1957 init_completion(&fs_info->kobj_unregister);
1958 INIT_LIST_HEAD(&fs_info->dirty_cowonly_roots);
1959 INIT_LIST_HEAD(&fs_info->space_info);
1960 btrfs_mapping_init(&fs_info->mapping_tree);
1961 btrfs_init_block_rsv(&fs_info->global_block_rsv);
1962 btrfs_init_block_rsv(&fs_info->delalloc_block_rsv);
1963 btrfs_init_block_rsv(&fs_info->trans_block_rsv);
1964 btrfs_init_block_rsv(&fs_info->chunk_block_rsv);
1965 btrfs_init_block_rsv(&fs_info->empty_block_rsv);
1966 btrfs_init_block_rsv(&fs_info->delayed_block_rsv);
1967 atomic_set(&fs_info->nr_async_submits, 0);
1968 atomic_set(&fs_info->async_delalloc_pages, 0);
1969 atomic_set(&fs_info->async_submit_draining, 0);
1970 atomic_set(&fs_info->nr_async_bios, 0);
1971 atomic_set(&fs_info->defrag_running, 0);
1972 fs_info->sb = sb;
1973 fs_info->max_inline = 8192 * 1024;
1974 fs_info->metadata_ratio = 0;
1975 fs_info->defrag_inodes = RB_ROOT;
1976 fs_info->trans_no_join = 0;
1977 fs_info->free_chunk_space = 0;
1978
1979 /* readahead state */
1980 INIT_RADIX_TREE(&fs_info->reada_tree, GFP_NOFS & ~__GFP_WAIT);
1981 spin_lock_init(&fs_info->reada_lock);
1982
1983 fs_info->thread_pool_size = min_t(unsigned long,
1984 num_online_cpus() + 2, 8);
1985
1986 INIT_LIST_HEAD(&fs_info->ordered_extents);
1987 spin_lock_init(&fs_info->ordered_extent_lock);
1988 fs_info->delayed_root = kmalloc(sizeof(struct btrfs_delayed_root),
1989 GFP_NOFS);
1990 if (!fs_info->delayed_root) {
1991 err = -ENOMEM;
1992 goto fail_iput;
1993 }
1994 btrfs_init_delayed_root(fs_info->delayed_root);
1995
1996 mutex_init(&fs_info->scrub_lock);
1997 atomic_set(&fs_info->scrubs_running, 0);
1998 atomic_set(&fs_info->scrub_pause_req, 0);
1999 atomic_set(&fs_info->scrubs_paused, 0);
2000 atomic_set(&fs_info->scrub_cancel_req, 0);
2001 init_waitqueue_head(&fs_info->scrub_pause_wait);
2002 init_rwsem(&fs_info->scrub_super_lock);
2003 fs_info->scrub_workers_refcnt = 0;
2004
2005 sb->s_blocksize = 4096;
2006 sb->s_blocksize_bits = blksize_bits(4096);
2007 sb->s_bdi = &fs_info->bdi;
2008
2009 fs_info->btree_inode->i_ino = BTRFS_BTREE_INODE_OBJECTID;
2010 set_nlink(fs_info->btree_inode, 1);
2011 /*
2012 * we set the i_size on the btree inode to the max possible int.
2013 * the real end of the address space is determined by all of
2014 * the devices in the system
2015 */
2016 fs_info->btree_inode->i_size = OFFSET_MAX;
2017 fs_info->btree_inode->i_mapping->a_ops = &btree_aops;
2018 fs_info->btree_inode->i_mapping->backing_dev_info = &fs_info->bdi;
2019
2020 RB_CLEAR_NODE(&BTRFS_I(fs_info->btree_inode)->rb_node);
2021 extent_io_tree_init(&BTRFS_I(fs_info->btree_inode)->io_tree,
2022 fs_info->btree_inode->i_mapping);
2023 extent_map_tree_init(&BTRFS_I(fs_info->btree_inode)->extent_tree);
2024
2025 BTRFS_I(fs_info->btree_inode)->io_tree.ops = &btree_extent_io_ops;
2026
2027 BTRFS_I(fs_info->btree_inode)->root = tree_root;
2028 memset(&BTRFS_I(fs_info->btree_inode)->location, 0,
2029 sizeof(struct btrfs_key));
2030 BTRFS_I(fs_info->btree_inode)->dummy_inode = 1;
2031 insert_inode_hash(fs_info->btree_inode);
2032
2033 spin_lock_init(&fs_info->block_group_cache_lock);
2034 fs_info->block_group_cache_tree = RB_ROOT;
2035
2036 extent_io_tree_init(&fs_info->freed_extents[0],
2037 fs_info->btree_inode->i_mapping);
2038 extent_io_tree_init(&fs_info->freed_extents[1],
2039 fs_info->btree_inode->i_mapping);
2040 fs_info->pinned_extents = &fs_info->freed_extents[0];
2041 fs_info->do_barriers = 1;
2042
2043
2044 mutex_init(&fs_info->ordered_operations_mutex);
2045 mutex_init(&fs_info->tree_log_mutex);
2046 mutex_init(&fs_info->chunk_mutex);
2047 mutex_init(&fs_info->transaction_kthread_mutex);
2048 mutex_init(&fs_info->cleaner_mutex);
2049 mutex_init(&fs_info->volume_mutex);
2050 init_rwsem(&fs_info->extent_commit_sem);
2051 init_rwsem(&fs_info->cleanup_work_sem);
2052 init_rwsem(&fs_info->subvol_sem);
2053
2054 btrfs_init_free_cluster(&fs_info->meta_alloc_cluster);
2055 btrfs_init_free_cluster(&fs_info->data_alloc_cluster);
2056
2057 init_waitqueue_head(&fs_info->transaction_throttle);
2058 init_waitqueue_head(&fs_info->transaction_wait);
2059 init_waitqueue_head(&fs_info->transaction_blocked_wait);
2060 init_waitqueue_head(&fs_info->async_submit_wait);
2061
2062 __setup_root(4096, 4096, 4096, 4096, tree_root,
2063 fs_info, BTRFS_ROOT_TREE_OBJECTID);
2064
2065 bh = btrfs_read_dev_super(fs_devices->latest_bdev);
2066 if (!bh) {
2067 err = -EINVAL;
2068 goto fail_alloc;
2069 }
2070
2071 memcpy(fs_info->super_copy, bh->b_data, sizeof(*fs_info->super_copy));
2072 memcpy(fs_info->super_for_commit, fs_info->super_copy,
2073 sizeof(*fs_info->super_for_commit));
2074 brelse(bh);
2075
2076 memcpy(fs_info->fsid, fs_info->super_copy->fsid, BTRFS_FSID_SIZE);
2077
2078 disk_super = fs_info->super_copy;
2079 if (!btrfs_super_root(disk_super))
2080 goto fail_alloc;
2081
2082 /* check FS state, whether FS is broken. */
2083 fs_info->fs_state |= btrfs_super_flags(disk_super);
2084
2085 btrfs_check_super_valid(fs_info, sb->s_flags & MS_RDONLY);
2086
2087 /*
2088 * run through our array of backup supers and setup
2089 * our ring pointer to the oldest one
2090 */
2091 generation = btrfs_super_generation(disk_super);
2092 find_oldest_super_backup(fs_info, generation);
2093
2094 /*
2095 * In the long term, we'll store the compression type in the super
2096 * block, and it'll be used for per file compression control.
2097 */
2098 fs_info->compress_type = BTRFS_COMPRESS_ZLIB;
2099
2100 ret = btrfs_parse_options(tree_root, options);
2101 if (ret) {
2102 err = ret;
2103 goto fail_alloc;
2104 }
2105
2106 features = btrfs_super_incompat_flags(disk_super) &
2107 ~BTRFS_FEATURE_INCOMPAT_SUPP;
2108 if (features) {
2109 printk(KERN_ERR "BTRFS: couldn't mount because of "
2110 "unsupported optional features (%Lx).\n",
2111 (unsigned long long)features);
2112 err = -EINVAL;
2113 goto fail_alloc;
2114 }
2115
2116 features = btrfs_super_incompat_flags(disk_super);
2117 features |= BTRFS_FEATURE_INCOMPAT_MIXED_BACKREF;
2118 if (tree_root->fs_info->compress_type & BTRFS_COMPRESS_LZO)
2119 features |= BTRFS_FEATURE_INCOMPAT_COMPRESS_LZO;
2120 btrfs_set_super_incompat_flags(disk_super, features);
2121
2122 features = btrfs_super_compat_ro_flags(disk_super) &
2123 ~BTRFS_FEATURE_COMPAT_RO_SUPP;
2124 if (!(sb->s_flags & MS_RDONLY) && features) {
2125 printk(KERN_ERR "BTRFS: couldn't mount RDWR because of "
2126 "unsupported option features (%Lx).\n",
2127 (unsigned long long)features);
2128 err = -EINVAL;
2129 goto fail_alloc;
2130 }
2131
2132 btrfs_init_workers(&fs_info->generic_worker,
2133 "genwork", 1, NULL);
2134
2135 btrfs_init_workers(&fs_info->workers, "worker",
2136 fs_info->thread_pool_size,
2137 &fs_info->generic_worker);
2138
2139 btrfs_init_workers(&fs_info->delalloc_workers, "delalloc",
2140 fs_info->thread_pool_size,
2141 &fs_info->generic_worker);
2142
2143 btrfs_init_workers(&fs_info->submit_workers, "submit",
2144 min_t(u64, fs_devices->num_devices,
2145 fs_info->thread_pool_size),
2146 &fs_info->generic_worker);
2147
2148 btrfs_init_workers(&fs_info->caching_workers, "cache",
2149 2, &fs_info->generic_worker);
2150
2151 /* a higher idle thresh on the submit workers makes it much more
2152 * likely that bios will be send down in a sane order to the
2153 * devices
2154 */
2155 fs_info->submit_workers.idle_thresh = 64;
2156
2157 fs_info->workers.idle_thresh = 16;
2158 fs_info->workers.ordered = 1;
2159
2160 fs_info->delalloc_workers.idle_thresh = 2;
2161 fs_info->delalloc_workers.ordered = 1;
2162
2163 btrfs_init_workers(&fs_info->fixup_workers, "fixup", 1,
2164 &fs_info->generic_worker);
2165 btrfs_init_workers(&fs_info->endio_workers, "endio",
2166 fs_info->thread_pool_size,
2167 &fs_info->generic_worker);
2168 btrfs_init_workers(&fs_info->endio_meta_workers, "endio-meta",
2169 fs_info->thread_pool_size,
2170 &fs_info->generic_worker);
2171 btrfs_init_workers(&fs_info->endio_meta_write_workers,
2172 "endio-meta-write", fs_info->thread_pool_size,
2173 &fs_info->generic_worker);
2174 btrfs_init_workers(&fs_info->endio_write_workers, "endio-write",
2175 fs_info->thread_pool_size,
2176 &fs_info->generic_worker);
2177 btrfs_init_workers(&fs_info->endio_freespace_worker, "freespace-write",
2178 1, &fs_info->generic_worker);
2179 btrfs_init_workers(&fs_info->delayed_workers, "delayed-meta",
2180 fs_info->thread_pool_size,
2181 &fs_info->generic_worker);
2182 btrfs_init_workers(&fs_info->readahead_workers, "readahead",
2183 fs_info->thread_pool_size,
2184 &fs_info->generic_worker);
2185
2186 /*
2187 * endios are largely parallel and should have a very
2188 * low idle thresh
2189 */
2190 fs_info->endio_workers.idle_thresh = 4;
2191 fs_info->endio_meta_workers.idle_thresh = 4;
2192
2193 fs_info->endio_write_workers.idle_thresh = 2;
2194 fs_info->endio_meta_write_workers.idle_thresh = 2;
2195 fs_info->readahead_workers.idle_thresh = 2;
2196
2197 btrfs_start_workers(&fs_info->workers, 1);
2198 btrfs_start_workers(&fs_info->generic_worker, 1);
2199 btrfs_start_workers(&fs_info->submit_workers, 1);
2200 btrfs_start_workers(&fs_info->delalloc_workers, 1);
2201 btrfs_start_workers(&fs_info->fixup_workers, 1);
2202 btrfs_start_workers(&fs_info->endio_workers, 1);
2203 btrfs_start_workers(&fs_info->endio_meta_workers, 1);
2204 btrfs_start_workers(&fs_info->endio_meta_write_workers, 1);
2205 btrfs_start_workers(&fs_info->endio_write_workers, 1);
2206 btrfs_start_workers(&fs_info->endio_freespace_worker, 1);
2207 btrfs_start_workers(&fs_info->delayed_workers, 1);
2208 btrfs_start_workers(&fs_info->caching_workers, 1);
2209 btrfs_start_workers(&fs_info->readahead_workers, 1);
2210
2211 fs_info->bdi.ra_pages *= btrfs_super_num_devices(disk_super);
2212 fs_info->bdi.ra_pages = max(fs_info->bdi.ra_pages,
2213 4 * 1024 * 1024 / PAGE_CACHE_SIZE);
2214
2215 nodesize = btrfs_super_nodesize(disk_super);
2216 leafsize = btrfs_super_leafsize(disk_super);
2217 sectorsize = btrfs_super_sectorsize(disk_super);
2218 stripesize = btrfs_super_stripesize(disk_super);
2219 tree_root->nodesize = nodesize;
2220 tree_root->leafsize = leafsize;
2221 tree_root->sectorsize = sectorsize;
2222 tree_root->stripesize = stripesize;
2223
2224 sb->s_blocksize = sectorsize;
2225 sb->s_blocksize_bits = blksize_bits(sectorsize);
2226
2227 if (strncmp((char *)(&disk_super->magic), BTRFS_MAGIC,
2228 sizeof(disk_super->magic))) {
2229 printk(KERN_INFO "btrfs: valid FS not found on %s\n", sb->s_id);
2230 goto fail_sb_buffer;
2231 }
2232
2233 mutex_lock(&fs_info->chunk_mutex);
2234 ret = btrfs_read_sys_array(tree_root);
2235 mutex_unlock(&fs_info->chunk_mutex);
2236 if (ret) {
2237 printk(KERN_WARNING "btrfs: failed to read the system "
2238 "array on %s\n", sb->s_id);
2239 goto fail_sb_buffer;
2240 }
2241
2242 blocksize = btrfs_level_size(tree_root,
2243 btrfs_super_chunk_root_level(disk_super));
2244 generation = btrfs_super_chunk_root_generation(disk_super);
2245
2246 __setup_root(nodesize, leafsize, sectorsize, stripesize,
2247 chunk_root, fs_info, BTRFS_CHUNK_TREE_OBJECTID);
2248
2249 chunk_root->node = read_tree_block(chunk_root,
2250 btrfs_super_chunk_root(disk_super),
2251 blocksize, generation);
2252 BUG_ON(!chunk_root->node);
2253 if (!test_bit(EXTENT_BUFFER_UPTODATE, &chunk_root->node->bflags)) {
2254 printk(KERN_WARNING "btrfs: failed to read chunk root on %s\n",
2255 sb->s_id);
2256 goto fail_tree_roots;
2257 }
2258 btrfs_set_root_node(&chunk_root->root_item, chunk_root->node);
2259 chunk_root->commit_root = btrfs_root_node(chunk_root);
2260
2261 read_extent_buffer(chunk_root->node, fs_info->chunk_tree_uuid,
2262 (unsigned long)btrfs_header_chunk_tree_uuid(chunk_root->node),
2263 BTRFS_UUID_SIZE);
2264
2265 mutex_lock(&fs_info->chunk_mutex);
2266 ret = btrfs_read_chunk_tree(chunk_root);
2267 mutex_unlock(&fs_info->chunk_mutex);
2268 if (ret) {
2269 printk(KERN_WARNING "btrfs: failed to read chunk tree on %s\n",
2270 sb->s_id);
2271 goto fail_tree_roots;
2272 }
2273
2274 btrfs_close_extra_devices(fs_devices);
2275
2276 retry_root_backup:
2277 blocksize = btrfs_level_size(tree_root,
2278 btrfs_super_root_level(disk_super));
2279 generation = btrfs_super_generation(disk_super);
2280
2281 tree_root->node = read_tree_block(tree_root,
2282 btrfs_super_root(disk_super),
2283 blocksize, generation);
2284 if (!tree_root->node ||
2285 !test_bit(EXTENT_BUFFER_UPTODATE, &tree_root->node->bflags)) {
2286 printk(KERN_WARNING "btrfs: failed to read tree root on %s\n",
2287 sb->s_id);
2288
2289 goto recovery_tree_root;
2290 }
2291
2292 btrfs_set_root_node(&tree_root->root_item, tree_root->node);
2293 tree_root->commit_root = btrfs_root_node(tree_root);
2294
2295 ret = find_and_setup_root(tree_root, fs_info,
2296 BTRFS_EXTENT_TREE_OBJECTID, extent_root);
2297 if (ret)
2298 goto recovery_tree_root;
2299 extent_root->track_dirty = 1;
2300
2301 ret = find_and_setup_root(tree_root, fs_info,
2302 BTRFS_DEV_TREE_OBJECTID, dev_root);
2303 if (ret)
2304 goto recovery_tree_root;
2305 dev_root->track_dirty = 1;
2306
2307 ret = find_and_setup_root(tree_root, fs_info,
2308 BTRFS_CSUM_TREE_OBJECTID, csum_root);
2309 if (ret)
2310 goto recovery_tree_root;
2311
2312 csum_root->track_dirty = 1;
2313
2314 fs_info->generation = generation;
2315 fs_info->last_trans_committed = generation;
2316 fs_info->data_alloc_profile = (u64)-1;
2317 fs_info->metadata_alloc_profile = (u64)-1;
2318 fs_info->system_alloc_profile = fs_info->metadata_alloc_profile;
2319
2320 ret = btrfs_init_space_info(fs_info);
2321 if (ret) {
2322 printk(KERN_ERR "Failed to initial space info: %d\n", ret);
2323 goto fail_block_groups;
2324 }
2325
2326 ret = btrfs_read_block_groups(extent_root);
2327 if (ret) {
2328 printk(KERN_ERR "Failed to read block groups: %d\n", ret);
2329 goto fail_block_groups;
2330 }
2331
2332 fs_info->cleaner_kthread = kthread_run(cleaner_kthread, tree_root,
2333 "btrfs-cleaner");
2334 if (IS_ERR(fs_info->cleaner_kthread))
2335 goto fail_block_groups;
2336
2337 fs_info->transaction_kthread = kthread_run(transaction_kthread,
2338 tree_root,
2339 "btrfs-transaction");
2340 if (IS_ERR(fs_info->transaction_kthread))
2341 goto fail_cleaner;
2342
2343 if (!btrfs_test_opt(tree_root, SSD) &&
2344 !btrfs_test_opt(tree_root, NOSSD) &&
2345 !fs_info->fs_devices->rotating) {
2346 printk(KERN_INFO "Btrfs detected SSD devices, enabling SSD "
2347 "mode\n");
2348 btrfs_set_opt(fs_info->mount_opt, SSD);
2349 }
2350
2351 /* do not make disk changes in broken FS */
2352 if (btrfs_super_log_root(disk_super) != 0 &&
2353 !(fs_info->fs_state & BTRFS_SUPER_FLAG_ERROR)) {
2354 u64 bytenr = btrfs_super_log_root(disk_super);
2355
2356 if (fs_devices->rw_devices == 0) {
2357 printk(KERN_WARNING "Btrfs log replay required "
2358 "on RO media\n");
2359 err = -EIO;
2360 goto fail_trans_kthread;
2361 }
2362 blocksize =
2363 btrfs_level_size(tree_root,
2364 btrfs_super_log_root_level(disk_super));
2365
2366 log_tree_root = kzalloc(sizeof(struct btrfs_root), GFP_NOFS);
2367 if (!log_tree_root) {
2368 err = -ENOMEM;
2369 goto fail_trans_kthread;
2370 }
2371
2372 __setup_root(nodesize, leafsize, sectorsize, stripesize,
2373 log_tree_root, fs_info, BTRFS_TREE_LOG_OBJECTID);
2374
2375 log_tree_root->node = read_tree_block(tree_root, bytenr,
2376 blocksize,
2377 generation + 1);
2378 ret = btrfs_recover_log_trees(log_tree_root);
2379 BUG_ON(ret);
2380
2381 if (sb->s_flags & MS_RDONLY) {
2382 ret = btrfs_commit_super(tree_root);
2383 BUG_ON(ret);
2384 }
2385 }
2386
2387 ret = btrfs_find_orphan_roots(tree_root);
2388 BUG_ON(ret);
2389
2390 if (!(sb->s_flags & MS_RDONLY)) {
2391 ret = btrfs_cleanup_fs_roots(fs_info);
2392 BUG_ON(ret);
2393
2394 ret = btrfs_recover_relocation(tree_root);
2395 if (ret < 0) {
2396 printk(KERN_WARNING
2397 "btrfs: failed to recover relocation\n");
2398 err = -EINVAL;
2399 goto fail_trans_kthread;
2400 }
2401 }
2402
2403 location.objectid = BTRFS_FS_TREE_OBJECTID;
2404 location.type = BTRFS_ROOT_ITEM_KEY;
2405 location.offset = (u64)-1;
2406
2407 fs_info->fs_root = btrfs_read_fs_root_no_name(fs_info, &location);
2408 if (!fs_info->fs_root)
2409 goto fail_trans_kthread;
2410 if (IS_ERR(fs_info->fs_root)) {
2411 err = PTR_ERR(fs_info->fs_root);
2412 goto fail_trans_kthread;
2413 }
2414
2415 if (!(sb->s_flags & MS_RDONLY)) {
2416 down_read(&fs_info->cleanup_work_sem);
2417 err = btrfs_orphan_cleanup(fs_info->fs_root);
2418 if (!err)
2419 err = btrfs_orphan_cleanup(fs_info->tree_root);
2420 up_read(&fs_info->cleanup_work_sem);
2421 if (err) {
2422 close_ctree(tree_root);
2423 return ERR_PTR(err);
2424 }
2425 }
2426
2427 return tree_root;
2428
2429 fail_trans_kthread:
2430 kthread_stop(fs_info->transaction_kthread);
2431 fail_cleaner:
2432 kthread_stop(fs_info->cleaner_kthread);
2433
2434 /*
2435 * make sure we're done with the btree inode before we stop our
2436 * kthreads
2437 */
2438 filemap_write_and_wait(fs_info->btree_inode->i_mapping);
2439 invalidate_inode_pages2(fs_info->btree_inode->i_mapping);
2440
2441 fail_block_groups:
2442 btrfs_free_block_groups(fs_info);
2443
2444 fail_tree_roots:
2445 free_root_pointers(fs_info, 1);
2446
2447 fail_sb_buffer:
2448 btrfs_stop_workers(&fs_info->generic_worker);
2449 btrfs_stop_workers(&fs_info->readahead_workers);
2450 btrfs_stop_workers(&fs_info->fixup_workers);
2451 btrfs_stop_workers(&fs_info->delalloc_workers);
2452 btrfs_stop_workers(&fs_info->workers);
2453 btrfs_stop_workers(&fs_info->endio_workers);
2454 btrfs_stop_workers(&fs_info->endio_meta_workers);
2455 btrfs_stop_workers(&fs_info->endio_meta_write_workers);
2456 btrfs_stop_workers(&fs_info->endio_write_workers);
2457 btrfs_stop_workers(&fs_info->endio_freespace_worker);
2458 btrfs_stop_workers(&fs_info->submit_workers);
2459 btrfs_stop_workers(&fs_info->delayed_workers);
2460 btrfs_stop_workers(&fs_info->caching_workers);
2461 fail_alloc:
2462 fail_iput:
2463 btrfs_mapping_tree_free(&fs_info->mapping_tree);
2464
2465 invalidate_inode_pages2(fs_info->btree_inode->i_mapping);
2466 iput(fs_info->btree_inode);
2467 fail_bdi:
2468 bdi_destroy(&fs_info->bdi);
2469 fail_srcu:
2470 cleanup_srcu_struct(&fs_info->subvol_srcu);
2471 fail:
2472 btrfs_close_devices(fs_info->fs_devices);
2473 free_fs_info(fs_info);
2474 return ERR_PTR(err);
2475
2476 recovery_tree_root:
2477 if (!btrfs_test_opt(tree_root, RECOVERY))
2478 goto fail_tree_roots;
2479
2480 free_root_pointers(fs_info, 0);
2481
2482 /* don't use the log in recovery mode, it won't be valid */
2483 btrfs_set_super_log_root(disk_super, 0);
2484
2485 /* we can't trust the free space cache either */
2486 btrfs_set_opt(fs_info->mount_opt, CLEAR_CACHE);
2487
2488 ret = next_root_backup(fs_info, fs_info->super_copy,
2489 &num_backups_tried, &backup_index);
2490 if (ret == -1)
2491 goto fail_block_groups;
2492 goto retry_root_backup;
2493 }
2494
2495 static void btrfs_end_buffer_write_sync(struct buffer_head *bh, int uptodate)
2496 {
2497 char b[BDEVNAME_SIZE];
2498
2499 if (uptodate) {
2500 set_buffer_uptodate(bh);
2501 } else {
2502 printk_ratelimited(KERN_WARNING "lost page write due to "
2503 "I/O error on %s\n",
2504 bdevname(bh->b_bdev, b));
2505 /* note, we dont' set_buffer_write_io_error because we have
2506 * our own ways of dealing with the IO errors
2507 */
2508 clear_buffer_uptodate(bh);
2509 }
2510 unlock_buffer(bh);
2511 put_bh(bh);
2512 }
2513
2514 struct buffer_head *btrfs_read_dev_super(struct block_device *bdev)
2515 {
2516 struct buffer_head *bh;
2517 struct buffer_head *latest = NULL;
2518 struct btrfs_super_block *super;
2519 int i;
2520 u64 transid = 0;
2521 u64 bytenr;
2522
2523 /* we would like to check all the supers, but that would make
2524 * a btrfs mount succeed after a mkfs from a different FS.
2525 * So, we need to add a special mount option to scan for
2526 * later supers, using BTRFS_SUPER_MIRROR_MAX instead
2527 */
2528 for (i = 0; i < 1; i++) {
2529 bytenr = btrfs_sb_offset(i);
2530 if (bytenr + 4096 >= i_size_read(bdev->bd_inode))
2531 break;
2532 bh = __bread(bdev, bytenr / 4096, 4096);
2533 if (!bh)
2534 continue;
2535
2536 super = (struct btrfs_super_block *)bh->b_data;
2537 if (btrfs_super_bytenr(super) != bytenr ||
2538 strncmp((char *)(&super->magic), BTRFS_MAGIC,
2539 sizeof(super->magic))) {
2540 brelse(bh);
2541 continue;
2542 }
2543
2544 if (!latest || btrfs_super_generation(super) > transid) {
2545 brelse(latest);
2546 latest = bh;
2547 transid = btrfs_super_generation(super);
2548 } else {
2549 brelse(bh);
2550 }
2551 }
2552 return latest;
2553 }
2554
2555 /*
2556 * this should be called twice, once with wait == 0 and
2557 * once with wait == 1. When wait == 0 is done, all the buffer heads
2558 * we write are pinned.
2559 *
2560 * They are released when wait == 1 is done.
2561 * max_mirrors must be the same for both runs, and it indicates how
2562 * many supers on this one device should be written.
2563 *
2564 * max_mirrors == 0 means to write them all.
2565 */
2566 static int write_dev_supers(struct btrfs_device *device,
2567 struct btrfs_super_block *sb,
2568 int do_barriers, int wait, int max_mirrors)
2569 {
2570 struct buffer_head *bh;
2571 int i;
2572 int ret;
2573 int errors = 0;
2574 u32 crc;
2575 u64 bytenr;
2576
2577 if (max_mirrors == 0)
2578 max_mirrors = BTRFS_SUPER_MIRROR_MAX;
2579
2580 for (i = 0; i < max_mirrors; i++) {
2581 bytenr = btrfs_sb_offset(i);
2582 if (bytenr + BTRFS_SUPER_INFO_SIZE >= device->total_bytes)
2583 break;
2584
2585 if (wait) {
2586 bh = __find_get_block(device->bdev, bytenr / 4096,
2587 BTRFS_SUPER_INFO_SIZE);
2588 BUG_ON(!bh);
2589 wait_on_buffer(bh);
2590 if (!buffer_uptodate(bh))
2591 errors++;
2592
2593 /* drop our reference */
2594 brelse(bh);
2595
2596 /* drop the reference from the wait == 0 run */
2597 brelse(bh);
2598 continue;
2599 } else {
2600 btrfs_set_super_bytenr(sb, bytenr);
2601
2602 crc = ~(u32)0;
2603 crc = btrfs_csum_data(NULL, (char *)sb +
2604 BTRFS_CSUM_SIZE, crc,
2605 BTRFS_SUPER_INFO_SIZE -
2606 BTRFS_CSUM_SIZE);
2607 btrfs_csum_final(crc, sb->csum);
2608
2609 /*
2610 * one reference for us, and we leave it for the
2611 * caller
2612 */
2613 bh = __getblk(device->bdev, bytenr / 4096,
2614 BTRFS_SUPER_INFO_SIZE);
2615 memcpy(bh->b_data, sb, BTRFS_SUPER_INFO_SIZE);
2616
2617 /* one reference for submit_bh */
2618 get_bh(bh);
2619
2620 set_buffer_uptodate(bh);
2621 lock_buffer(bh);
2622 bh->b_end_io = btrfs_end_buffer_write_sync;
2623 }
2624
2625 /*
2626 * we fua the first super. The others we allow
2627 * to go down lazy.
2628 */
2629 ret = submit_bh(WRITE_FUA, bh);
2630 if (ret)
2631 errors++;
2632 }
2633 return errors < i ? 0 : -1;
2634 }
2635
2636 /*
2637 * endio for the write_dev_flush, this will wake anyone waiting
2638 * for the barrier when it is done
2639 */
2640 static void btrfs_end_empty_barrier(struct bio *bio, int err)
2641 {
2642 if (err) {
2643 if (err == -EOPNOTSUPP)
2644 set_bit(BIO_EOPNOTSUPP, &bio->bi_flags);
2645 clear_bit(BIO_UPTODATE, &bio->bi_flags);
2646 }
2647 if (bio->bi_private)
2648 complete(bio->bi_private);
2649 bio_put(bio);
2650 }
2651
2652 /*
2653 * trigger flushes for one the devices. If you pass wait == 0, the flushes are
2654 * sent down. With wait == 1, it waits for the previous flush.
2655 *
2656 * any device where the flush fails with eopnotsupp are flagged as not-barrier
2657 * capable
2658 */
2659 static int write_dev_flush(struct btrfs_device *device, int wait)
2660 {
2661 struct bio *bio;
2662 int ret = 0;
2663
2664 if (device->nobarriers)
2665 return 0;
2666
2667 if (wait) {
2668 bio = device->flush_bio;
2669 if (!bio)
2670 return 0;
2671
2672 wait_for_completion(&device->flush_wait);
2673
2674 if (bio_flagged(bio, BIO_EOPNOTSUPP)) {
2675 printk("btrfs: disabling barriers on dev %s\n",
2676 device->name);
2677 device->nobarriers = 1;
2678 }
2679 if (!bio_flagged(bio, BIO_UPTODATE)) {
2680 ret = -EIO;
2681 }
2682
2683 /* drop the reference from the wait == 0 run */
2684 bio_put(bio);
2685 device->flush_bio = NULL;
2686
2687 return ret;
2688 }
2689
2690 /*
2691 * one reference for us, and we leave it for the
2692 * caller
2693 */
2694 device->flush_bio = NULL;;
2695 bio = bio_alloc(GFP_NOFS, 0);
2696 if (!bio)
2697 return -ENOMEM;
2698
2699 bio->bi_end_io = btrfs_end_empty_barrier;
2700 bio->bi_bdev = device->bdev;
2701 init_completion(&device->flush_wait);
2702 bio->bi_private = &device->flush_wait;
2703 device->flush_bio = bio;
2704
2705 bio_get(bio);
2706 submit_bio(WRITE_FLUSH, bio);
2707
2708 return 0;
2709 }
2710
2711 /*
2712 * send an empty flush down to each device in parallel,
2713 * then wait for them
2714 */
2715 static int barrier_all_devices(struct btrfs_fs_info *info)
2716 {
2717 struct list_head *head;
2718 struct btrfs_device *dev;
2719 int errors = 0;
2720 int ret;
2721
2722 /* send down all the barriers */
2723 head = &info->fs_devices->devices;
2724 list_for_each_entry_rcu(dev, head, dev_list) {
2725 if (!dev->bdev) {
2726 errors++;
2727 continue;
2728 }
2729 if (!dev->in_fs_metadata || !dev->writeable)
2730 continue;
2731
2732 ret = write_dev_flush(dev, 0);
2733 if (ret)
2734 errors++;
2735 }
2736
2737 /* wait for all the barriers */
2738 list_for_each_entry_rcu(dev, head, dev_list) {
2739 if (!dev->bdev) {
2740 errors++;
2741 continue;
2742 }
2743 if (!dev->in_fs_metadata || !dev->writeable)
2744 continue;
2745
2746 ret = write_dev_flush(dev, 1);
2747 if (ret)
2748 errors++;
2749 }
2750 if (errors)
2751 return -EIO;
2752 return 0;
2753 }
2754
2755 int write_all_supers(struct btrfs_root *root, int max_mirrors)
2756 {
2757 struct list_head *head;
2758 struct btrfs_device *dev;
2759 struct btrfs_super_block *sb;
2760 struct btrfs_dev_item *dev_item;
2761 int ret;
2762 int do_barriers;
2763 int max_errors;
2764 int total_errors = 0;
2765 u64 flags;
2766
2767 max_errors = btrfs_super_num_devices(root->fs_info->super_copy) - 1;
2768 do_barriers = !btrfs_test_opt(root, NOBARRIER);
2769 backup_super_roots(root->fs_info);
2770
2771 sb = root->fs_info->super_for_commit;
2772 dev_item = &sb->dev_item;
2773
2774 mutex_lock(&root->fs_info->fs_devices->device_list_mutex);
2775 head = &root->fs_info->fs_devices->devices;
2776
2777 if (do_barriers)
2778 barrier_all_devices(root->fs_info);
2779
2780 list_for_each_entry_rcu(dev, head, dev_list) {
2781 if (!dev->bdev) {
2782 total_errors++;
2783 continue;
2784 }
2785 if (!dev->in_fs_metadata || !dev->writeable)
2786 continue;
2787
2788 btrfs_set_stack_device_generation(dev_item, 0);
2789 btrfs_set_stack_device_type(dev_item, dev->type);
2790 btrfs_set_stack_device_id(dev_item, dev->devid);
2791 btrfs_set_stack_device_total_bytes(dev_item, dev->total_bytes);
2792 btrfs_set_stack_device_bytes_used(dev_item, dev->bytes_used);
2793 btrfs_set_stack_device_io_align(dev_item, dev->io_align);
2794 btrfs_set_stack_device_io_width(dev_item, dev->io_width);
2795 btrfs_set_stack_device_sector_size(dev_item, dev->sector_size);
2796 memcpy(dev_item->uuid, dev->uuid, BTRFS_UUID_SIZE);
2797 memcpy(dev_item->fsid, dev->fs_devices->fsid, BTRFS_UUID_SIZE);
2798
2799 flags = btrfs_super_flags(sb);
2800 btrfs_set_super_flags(sb, flags | BTRFS_HEADER_FLAG_WRITTEN);
2801
2802 ret = write_dev_supers(dev, sb, do_barriers, 0, max_mirrors);
2803 if (ret)
2804 total_errors++;
2805 }
2806 if (total_errors > max_errors) {
2807 printk(KERN_ERR "btrfs: %d errors while writing supers\n",
2808 total_errors);
2809 BUG();
2810 }
2811
2812 total_errors = 0;
2813 list_for_each_entry_rcu(dev, head, dev_list) {
2814 if (!dev->bdev)
2815 continue;
2816 if (!dev->in_fs_metadata || !dev->writeable)
2817 continue;
2818
2819 ret = write_dev_supers(dev, sb, do_barriers, 1, max_mirrors);
2820 if (ret)
2821 total_errors++;
2822 }
2823 mutex_unlock(&root->fs_info->fs_devices->device_list_mutex);
2824 if (total_errors > max_errors) {
2825 printk(KERN_ERR "btrfs: %d errors while writing supers\n",
2826 total_errors);
2827 BUG();
2828 }
2829 return 0;
2830 }
2831
2832 int write_ctree_super(struct btrfs_trans_handle *trans,
2833 struct btrfs_root *root, int max_mirrors)
2834 {
2835 int ret;
2836
2837 ret = write_all_supers(root, max_mirrors);
2838 return ret;
2839 }
2840
2841 int btrfs_free_fs_root(struct btrfs_fs_info *fs_info, struct btrfs_root *root)
2842 {
2843 spin_lock(&fs_info->fs_roots_radix_lock);
2844 radix_tree_delete(&fs_info->fs_roots_radix,
2845 (unsigned long)root->root_key.objectid);
2846 spin_unlock(&fs_info->fs_roots_radix_lock);
2847
2848 if (btrfs_root_refs(&root->root_item) == 0)
2849 synchronize_srcu(&fs_info->subvol_srcu);
2850
2851 __btrfs_remove_free_space_cache(root->free_ino_pinned);
2852 __btrfs_remove_free_space_cache(root->free_ino_ctl);
2853 free_fs_root(root);
2854 return 0;
2855 }
2856
2857 static void free_fs_root(struct btrfs_root *root)
2858 {
2859 iput(root->cache_inode);
2860 WARN_ON(!RB_EMPTY_ROOT(&root->inode_tree));
2861 if (root->anon_dev)
2862 free_anon_bdev(root->anon_dev);
2863 free_extent_buffer(root->node);
2864 free_extent_buffer(root->commit_root);
2865 kfree(root->free_ino_ctl);
2866 kfree(root->free_ino_pinned);
2867 kfree(root->name);
2868 kfree(root);
2869 }
2870
2871 static int del_fs_roots(struct btrfs_fs_info *fs_info)
2872 {
2873 int ret;
2874 struct btrfs_root *gang[8];
2875 int i;
2876
2877 while (!list_empty(&fs_info->dead_roots)) {
2878 gang[0] = list_entry(fs_info->dead_roots.next,
2879 struct btrfs_root, root_list);
2880 list_del(&gang[0]->root_list);
2881
2882 if (gang[0]->in_radix) {
2883 btrfs_free_fs_root(fs_info, gang[0]);
2884 } else {
2885 free_extent_buffer(gang[0]->node);
2886 free_extent_buffer(gang[0]->commit_root);
2887 kfree(gang[0]);
2888 }
2889 }
2890
2891 while (1) {
2892 ret = radix_tree_gang_lookup(&fs_info->fs_roots_radix,
2893 (void **)gang, 0,
2894 ARRAY_SIZE(gang));
2895 if (!ret)
2896 break;
2897 for (i = 0; i < ret; i++)
2898 btrfs_free_fs_root(fs_info, gang[i]);
2899 }
2900 return 0;
2901 }
2902
2903 int btrfs_cleanup_fs_roots(struct btrfs_fs_info *fs_info)
2904 {
2905 u64 root_objectid = 0;
2906 struct btrfs_root *gang[8];
2907 int i;
2908 int ret;
2909
2910 while (1) {
2911 ret = radix_tree_gang_lookup(&fs_info->fs_roots_radix,
2912 (void **)gang, root_objectid,
2913 ARRAY_SIZE(gang));
2914 if (!ret)
2915 break;
2916
2917 root_objectid = gang[ret - 1]->root_key.objectid + 1;
2918 for (i = 0; i < ret; i++) {
2919 int err;
2920
2921 root_objectid = gang[i]->root_key.objectid;
2922 err = btrfs_orphan_cleanup(gang[i]);
2923 if (err)
2924 return err;
2925 }
2926 root_objectid++;
2927 }
2928 return 0;
2929 }
2930
2931 int btrfs_commit_super(struct btrfs_root *root)
2932 {
2933 struct btrfs_trans_handle *trans;
2934 int ret;
2935
2936 mutex_lock(&root->fs_info->cleaner_mutex);
2937 btrfs_run_delayed_iputs(root);
2938 btrfs_clean_old_snapshots(root);
2939 mutex_unlock(&root->fs_info->cleaner_mutex);
2940
2941 /* wait until ongoing cleanup work done */
2942 down_write(&root->fs_info->cleanup_work_sem);
2943 up_write(&root->fs_info->cleanup_work_sem);
2944
2945 trans = btrfs_join_transaction(root);
2946 if (IS_ERR(trans))
2947 return PTR_ERR(trans);
2948 ret = btrfs_commit_transaction(trans, root);
2949 BUG_ON(ret);
2950 /* run commit again to drop the original snapshot */
2951 trans = btrfs_join_transaction(root);
2952 if (IS_ERR(trans))
2953 return PTR_ERR(trans);
2954 btrfs_commit_transaction(trans, root);
2955 ret = btrfs_write_and_wait_transaction(NULL, root);
2956 BUG_ON(ret);
2957
2958 ret = write_ctree_super(NULL, root, 0);
2959 return ret;
2960 }
2961
2962 int close_ctree(struct btrfs_root *root)
2963 {
2964 struct btrfs_fs_info *fs_info = root->fs_info;
2965 int ret;
2966
2967 fs_info->closing = 1;
2968 smp_mb();
2969
2970 btrfs_scrub_cancel(root);
2971
2972 /* wait for any defraggers to finish */
2973 wait_event(fs_info->transaction_wait,
2974 (atomic_read(&fs_info->defrag_running) == 0));
2975
2976 /* clear out the rbtree of defraggable inodes */
2977 btrfs_run_defrag_inodes(root->fs_info);
2978
2979 /*
2980 * Here come 2 situations when btrfs is broken to flip readonly:
2981 *
2982 * 1. when btrfs flips readonly somewhere else before
2983 * btrfs_commit_super, sb->s_flags has MS_RDONLY flag,
2984 * and btrfs will skip to write sb directly to keep
2985 * ERROR state on disk.
2986 *
2987 * 2. when btrfs flips readonly just in btrfs_commit_super,
2988 * and in such case, btrfs cannot write sb via btrfs_commit_super,
2989 * and since fs_state has been set BTRFS_SUPER_FLAG_ERROR flag,
2990 * btrfs will cleanup all FS resources first and write sb then.
2991 */
2992 if (!(fs_info->sb->s_flags & MS_RDONLY)) {
2993 ret = btrfs_commit_super(root);
2994 if (ret)
2995 printk(KERN_ERR "btrfs: commit super ret %d\n", ret);
2996 }
2997
2998 if (fs_info->fs_state & BTRFS_SUPER_FLAG_ERROR) {
2999 ret = btrfs_error_commit_super(root);
3000 if (ret)
3001 printk(KERN_ERR "btrfs: commit super ret %d\n", ret);
3002 }
3003
3004 btrfs_put_block_group_cache(fs_info);
3005
3006 kthread_stop(root->fs_info->transaction_kthread);
3007 kthread_stop(root->fs_info->cleaner_kthread);
3008
3009 fs_info->closing = 2;
3010 smp_mb();
3011
3012 if (fs_info->delalloc_bytes) {
3013 printk(KERN_INFO "btrfs: at unmount delalloc count %llu\n",
3014 (unsigned long long)fs_info->delalloc_bytes);
3015 }
3016 if (fs_info->total_ref_cache_size) {
3017 printk(KERN_INFO "btrfs: at umount reference cache size %llu\n",
3018 (unsigned long long)fs_info->total_ref_cache_size);
3019 }
3020
3021 free_extent_buffer(fs_info->extent_root->node);
3022 free_extent_buffer(fs_info->extent_root->commit_root);
3023 free_extent_buffer(fs_info->tree_root->node);
3024 free_extent_buffer(fs_info->tree_root->commit_root);
3025 free_extent_buffer(root->fs_info->chunk_root->node);
3026 free_extent_buffer(root->fs_info->chunk_root->commit_root);
3027 free_extent_buffer(root->fs_info->dev_root->node);
3028 free_extent_buffer(root->fs_info->dev_root->commit_root);
3029 free_extent_buffer(root->fs_info->csum_root->node);
3030 free_extent_buffer(root->fs_info->csum_root->commit_root);
3031
3032 btrfs_free_block_groups(root->fs_info);
3033
3034 del_fs_roots(fs_info);
3035
3036 iput(fs_info->btree_inode);
3037
3038 btrfs_stop_workers(&fs_info->generic_worker);
3039 btrfs_stop_workers(&fs_info->fixup_workers);
3040 btrfs_stop_workers(&fs_info->delalloc_workers);
3041 btrfs_stop_workers(&fs_info->workers);
3042 btrfs_stop_workers(&fs_info->endio_workers);
3043 btrfs_stop_workers(&fs_info->endio_meta_workers);
3044 btrfs_stop_workers(&fs_info->endio_meta_write_workers);
3045 btrfs_stop_workers(&fs_info->endio_write_workers);
3046 btrfs_stop_workers(&fs_info->endio_freespace_worker);
3047 btrfs_stop_workers(&fs_info->submit_workers);
3048 btrfs_stop_workers(&fs_info->delayed_workers);
3049 btrfs_stop_workers(&fs_info->caching_workers);
3050 btrfs_stop_workers(&fs_info->readahead_workers);
3051
3052 btrfs_close_devices(fs_info->fs_devices);
3053 btrfs_mapping_tree_free(&fs_info->mapping_tree);
3054
3055 bdi_destroy(&fs_info->bdi);
3056 cleanup_srcu_struct(&fs_info->subvol_srcu);
3057
3058 free_fs_info(fs_info);
3059
3060 return 0;
3061 }
3062
3063 int btrfs_buffer_uptodate(struct extent_buffer *buf, u64 parent_transid)
3064 {
3065 int ret;
3066 struct inode *btree_inode = buf->first_page->mapping->host;
3067
3068 ret = extent_buffer_uptodate(&BTRFS_I(btree_inode)->io_tree, buf,
3069 NULL);
3070 if (!ret)
3071 return ret;
3072
3073 ret = verify_parent_transid(&BTRFS_I(btree_inode)->io_tree, buf,
3074 parent_transid);
3075 return !ret;
3076 }
3077
3078 int btrfs_set_buffer_uptodate(struct extent_buffer *buf)
3079 {
3080 struct inode *btree_inode = buf->first_page->mapping->host;
3081 return set_extent_buffer_uptodate(&BTRFS_I(btree_inode)->io_tree,
3082 buf);
3083 }
3084
3085 void btrfs_mark_buffer_dirty(struct extent_buffer *buf)
3086 {
3087 struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
3088 u64 transid = btrfs_header_generation(buf);
3089 struct inode *btree_inode = root->fs_info->btree_inode;
3090 int was_dirty;
3091
3092 btrfs_assert_tree_locked(buf);
3093 if (transid != root->fs_info->generation) {
3094 printk(KERN_CRIT "btrfs transid mismatch buffer %llu, "
3095 "found %llu running %llu\n",
3096 (unsigned long long)buf->start,
3097 (unsigned long long)transid,
3098 (unsigned long long)root->fs_info->generation);
3099 WARN_ON(1);
3100 }
3101 was_dirty = set_extent_buffer_dirty(&BTRFS_I(btree_inode)->io_tree,
3102 buf);
3103 if (!was_dirty) {
3104 spin_lock(&root->fs_info->delalloc_lock);
3105 root->fs_info->dirty_metadata_bytes += buf->len;
3106 spin_unlock(&root->fs_info->delalloc_lock);
3107 }
3108 }
3109
3110 void btrfs_btree_balance_dirty(struct btrfs_root *root, unsigned long nr)
3111 {
3112 /*
3113 * looks as though older kernels can get into trouble with
3114 * this code, they end up stuck in balance_dirty_pages forever
3115 */
3116 u64 num_dirty;
3117 unsigned long thresh = 32 * 1024 * 1024;
3118
3119 if (current->flags & PF_MEMALLOC)
3120 return;
3121
3122 btrfs_balance_delayed_items(root);
3123
3124 num_dirty = root->fs_info->dirty_metadata_bytes;
3125
3126 if (num_dirty > thresh) {
3127 balance_dirty_pages_ratelimited_nr(
3128 root->fs_info->btree_inode->i_mapping, 1);
3129 }
3130 return;
3131 }
3132
3133 void __btrfs_btree_balance_dirty(struct btrfs_root *root, unsigned long nr)
3134 {
3135 /*
3136 * looks as though older kernels can get into trouble with
3137 * this code, they end up stuck in balance_dirty_pages forever
3138 */
3139 u64 num_dirty;
3140 unsigned long thresh = 32 * 1024 * 1024;
3141
3142 if (current->flags & PF_MEMALLOC)
3143 return;
3144
3145 num_dirty = root->fs_info->dirty_metadata_bytes;
3146
3147 if (num_dirty > thresh) {
3148 balance_dirty_pages_ratelimited_nr(
3149 root->fs_info->btree_inode->i_mapping, 1);
3150 }
3151 return;
3152 }
3153
3154 int btrfs_read_buffer(struct extent_buffer *buf, u64 parent_transid)
3155 {
3156 struct btrfs_root *root = BTRFS_I(buf->first_page->mapping->host)->root;
3157 int ret;
3158 ret = btree_read_extent_buffer_pages(root, buf, 0, parent_transid);
3159 if (ret == 0)
3160 set_bit(EXTENT_BUFFER_UPTODATE, &buf->bflags);
3161 return ret;
3162 }
3163
3164 static int btree_lock_page_hook(struct page *page, void *data,
3165 void (*flush_fn)(void *))
3166 {
3167 struct inode *inode = page->mapping->host;
3168 struct btrfs_root *root = BTRFS_I(inode)->root;
3169 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
3170 struct extent_buffer *eb;
3171 unsigned long len;
3172 u64 bytenr = page_offset(page);
3173
3174 if (page->private == EXTENT_PAGE_PRIVATE)
3175 goto out;
3176
3177 len = page->private >> 2;
3178 eb = find_extent_buffer(io_tree, bytenr, len);
3179 if (!eb)
3180 goto out;
3181
3182 if (!btrfs_try_tree_write_lock(eb)) {
3183 flush_fn(data);
3184 btrfs_tree_lock(eb);
3185 }
3186 btrfs_set_header_flag(eb, BTRFS_HEADER_FLAG_WRITTEN);
3187
3188 if (test_and_clear_bit(EXTENT_BUFFER_DIRTY, &eb->bflags)) {
3189 spin_lock(&root->fs_info->delalloc_lock);
3190 if (root->fs_info->dirty_metadata_bytes >= eb->len)
3191 root->fs_info->dirty_metadata_bytes -= eb->len;
3192 else
3193 WARN_ON(1);
3194 spin_unlock(&root->fs_info->delalloc_lock);
3195 }
3196
3197 btrfs_tree_unlock(eb);
3198 free_extent_buffer(eb);
3199 out:
3200 if (!trylock_page(page)) {
3201 flush_fn(data);
3202 lock_page(page);
3203 }
3204 return 0;
3205 }
3206
3207 static void btrfs_check_super_valid(struct btrfs_fs_info *fs_info,
3208 int read_only)
3209 {
3210 if (read_only)
3211 return;
3212
3213 if (fs_info->fs_state & BTRFS_SUPER_FLAG_ERROR)
3214 printk(KERN_WARNING "warning: mount fs with errors, "
3215 "running btrfsck is recommended\n");
3216 }
3217
3218 int btrfs_error_commit_super(struct btrfs_root *root)
3219 {
3220 int ret;
3221
3222 mutex_lock(&root->fs_info->cleaner_mutex);
3223 btrfs_run_delayed_iputs(root);
3224 mutex_unlock(&root->fs_info->cleaner_mutex);
3225
3226 down_write(&root->fs_info->cleanup_work_sem);
3227 up_write(&root->fs_info->cleanup_work_sem);
3228
3229 /* cleanup FS via transaction */
3230 btrfs_cleanup_transaction(root);
3231
3232 ret = write_ctree_super(NULL, root, 0);
3233
3234 return ret;
3235 }
3236
3237 static int btrfs_destroy_ordered_operations(struct btrfs_root *root)
3238 {
3239 struct btrfs_inode *btrfs_inode;
3240 struct list_head splice;
3241
3242 INIT_LIST_HEAD(&splice);
3243
3244 mutex_lock(&root->fs_info->ordered_operations_mutex);
3245 spin_lock(&root->fs_info->ordered_extent_lock);
3246
3247 list_splice_init(&root->fs_info->ordered_operations, &splice);
3248 while (!list_empty(&splice)) {
3249 btrfs_inode = list_entry(splice.next, struct btrfs_inode,
3250 ordered_operations);
3251
3252 list_del_init(&btrfs_inode->ordered_operations);
3253
3254 btrfs_invalidate_inodes(btrfs_inode->root);
3255 }
3256
3257 spin_unlock(&root->fs_info->ordered_extent_lock);
3258 mutex_unlock(&root->fs_info->ordered_operations_mutex);
3259
3260 return 0;
3261 }
3262
3263 static int btrfs_destroy_ordered_extents(struct btrfs_root *root)
3264 {
3265 struct list_head splice;
3266 struct btrfs_ordered_extent *ordered;
3267 struct inode *inode;
3268
3269 INIT_LIST_HEAD(&splice);
3270
3271 spin_lock(&root->fs_info->ordered_extent_lock);
3272
3273 list_splice_init(&root->fs_info->ordered_extents, &splice);
3274 while (!list_empty(&splice)) {
3275 ordered = list_entry(splice.next, struct btrfs_ordered_extent,
3276 root_extent_list);
3277
3278 list_del_init(&ordered->root_extent_list);
3279 atomic_inc(&ordered->refs);
3280
3281 /* the inode may be getting freed (in sys_unlink path). */
3282 inode = igrab(ordered->inode);
3283
3284 spin_unlock(&root->fs_info->ordered_extent_lock);
3285 if (inode)
3286 iput(inode);
3287
3288 atomic_set(&ordered->refs, 1);
3289 btrfs_put_ordered_extent(ordered);
3290
3291 spin_lock(&root->fs_info->ordered_extent_lock);
3292 }
3293
3294 spin_unlock(&root->fs_info->ordered_extent_lock);
3295
3296 return 0;
3297 }
3298
3299 static int btrfs_destroy_delayed_refs(struct btrfs_transaction *trans,
3300 struct btrfs_root *root)
3301 {
3302 struct rb_node *node;
3303 struct btrfs_delayed_ref_root *delayed_refs;
3304 struct btrfs_delayed_ref_node *ref;
3305 int ret = 0;
3306
3307 delayed_refs = &trans->delayed_refs;
3308
3309 spin_lock(&delayed_refs->lock);
3310 if (delayed_refs->num_entries == 0) {
3311 spin_unlock(&delayed_refs->lock);
3312 printk(KERN_INFO "delayed_refs has NO entry\n");
3313 return ret;
3314 }
3315
3316 node = rb_first(&delayed_refs->root);
3317 while (node) {
3318 ref = rb_entry(node, struct btrfs_delayed_ref_node, rb_node);
3319 node = rb_next(node);
3320
3321 ref->in_tree = 0;
3322 rb_erase(&ref->rb_node, &delayed_refs->root);
3323 delayed_refs->num_entries--;
3324
3325 atomic_set(&ref->refs, 1);
3326 if (btrfs_delayed_ref_is_head(ref)) {
3327 struct btrfs_delayed_ref_head *head;
3328
3329 head = btrfs_delayed_node_to_head(ref);
3330 mutex_lock(&head->mutex);
3331 kfree(head->extent_op);
3332 delayed_refs->num_heads--;
3333 if (list_empty(&head->cluster))
3334 delayed_refs->num_heads_ready--;
3335 list_del_init(&head->cluster);
3336 mutex_unlock(&head->mutex);
3337 }
3338
3339 spin_unlock(&delayed_refs->lock);
3340 btrfs_put_delayed_ref(ref);
3341
3342 cond_resched();
3343 spin_lock(&delayed_refs->lock);
3344 }
3345
3346 spin_unlock(&delayed_refs->lock);
3347
3348 return ret;
3349 }
3350
3351 static int btrfs_destroy_pending_snapshots(struct btrfs_transaction *t)
3352 {
3353 struct btrfs_pending_snapshot *snapshot;
3354 struct list_head splice;
3355
3356 INIT_LIST_HEAD(&splice);
3357
3358 list_splice_init(&t->pending_snapshots, &splice);
3359
3360 while (!list_empty(&splice)) {
3361 snapshot = list_entry(splice.next,
3362 struct btrfs_pending_snapshot,
3363 list);
3364
3365 list_del_init(&snapshot->list);
3366
3367 kfree(snapshot);
3368 }
3369
3370 return 0;
3371 }
3372
3373 static int btrfs_destroy_delalloc_inodes(struct btrfs_root *root)
3374 {
3375 struct btrfs_inode *btrfs_inode;
3376 struct list_head splice;
3377
3378 INIT_LIST_HEAD(&splice);
3379
3380 spin_lock(&root->fs_info->delalloc_lock);
3381 list_splice_init(&root->fs_info->delalloc_inodes, &splice);
3382
3383 while (!list_empty(&splice)) {
3384 btrfs_inode = list_entry(splice.next, struct btrfs_inode,
3385 delalloc_inodes);
3386
3387 list_del_init(&btrfs_inode->delalloc_inodes);
3388
3389 btrfs_invalidate_inodes(btrfs_inode->root);
3390 }
3391
3392 spin_unlock(&root->fs_info->delalloc_lock);
3393
3394 return 0;
3395 }
3396
3397 static int btrfs_destroy_marked_extents(struct btrfs_root *root,
3398 struct extent_io_tree *dirty_pages,
3399 int mark)
3400 {
3401 int ret;
3402 struct page *page;
3403 struct inode *btree_inode = root->fs_info->btree_inode;
3404 struct extent_buffer *eb;
3405 u64 start = 0;
3406 u64 end;
3407 u64 offset;
3408 unsigned long index;
3409
3410 while (1) {
3411 ret = find_first_extent_bit(dirty_pages, start, &start, &end,
3412 mark);
3413 if (ret)
3414 break;
3415
3416 clear_extent_bits(dirty_pages, start, end, mark, GFP_NOFS);
3417 while (start <= end) {
3418 index = start >> PAGE_CACHE_SHIFT;
3419 start = (u64)(index + 1) << PAGE_CACHE_SHIFT;
3420 page = find_get_page(btree_inode->i_mapping, index);
3421 if (!page)
3422 continue;
3423 offset = page_offset(page);
3424
3425 spin_lock(&dirty_pages->buffer_lock);
3426 eb = radix_tree_lookup(
3427 &(&BTRFS_I(page->mapping->host)->io_tree)->buffer,
3428 offset >> PAGE_CACHE_SHIFT);
3429 spin_unlock(&dirty_pages->buffer_lock);
3430 if (eb) {
3431 ret = test_and_clear_bit(EXTENT_BUFFER_DIRTY,
3432 &eb->bflags);
3433 atomic_set(&eb->refs, 1);
3434 }
3435 if (PageWriteback(page))
3436 end_page_writeback(page);
3437
3438 lock_page(page);
3439 if (PageDirty(page)) {
3440 clear_page_dirty_for_io(page);
3441 spin_lock_irq(&page->mapping->tree_lock);
3442 radix_tree_tag_clear(&page->mapping->page_tree,
3443 page_index(page),
3444 PAGECACHE_TAG_DIRTY);
3445 spin_unlock_irq(&page->mapping->tree_lock);
3446 }
3447
3448 page->mapping->a_ops->invalidatepage(page, 0);
3449 unlock_page(page);
3450 }
3451 }
3452
3453 return ret;
3454 }
3455
3456 static int btrfs_destroy_pinned_extent(struct btrfs_root *root,
3457 struct extent_io_tree *pinned_extents)
3458 {
3459 struct extent_io_tree *unpin;
3460 u64 start;
3461 u64 end;
3462 int ret;
3463
3464 unpin = pinned_extents;
3465 while (1) {
3466 ret = find_first_extent_bit(unpin, 0, &start, &end,
3467 EXTENT_DIRTY);
3468 if (ret)
3469 break;
3470
3471 /* opt_discard */
3472 if (btrfs_test_opt(root, DISCARD))
3473 ret = btrfs_error_discard_extent(root, start,
3474 end + 1 - start,
3475 NULL);
3476
3477 clear_extent_dirty(unpin, start, end, GFP_NOFS);
3478 btrfs_error_unpin_extent_range(root, start, end);
3479 cond_resched();
3480 }
3481
3482 return 0;
3483 }
3484
3485 static int btrfs_cleanup_transaction(struct btrfs_root *root)
3486 {
3487 struct btrfs_transaction *t;
3488 LIST_HEAD(list);
3489
3490 WARN_ON(1);
3491
3492 mutex_lock(&root->fs_info->transaction_kthread_mutex);
3493
3494 spin_lock(&root->fs_info->trans_lock);
3495 list_splice_init(&root->fs_info->trans_list, &list);
3496 root->fs_info->trans_no_join = 1;
3497 spin_unlock(&root->fs_info->trans_lock);
3498
3499 while (!list_empty(&list)) {
3500 t = list_entry(list.next, struct btrfs_transaction, list);
3501 if (!t)
3502 break;
3503
3504 btrfs_destroy_ordered_operations(root);
3505
3506 btrfs_destroy_ordered_extents(root);
3507
3508 btrfs_destroy_delayed_refs(t, root);
3509
3510 btrfs_block_rsv_release(root,
3511 &root->fs_info->trans_block_rsv,
3512 t->dirty_pages.dirty_bytes);
3513
3514 /* FIXME: cleanup wait for commit */
3515 t->in_commit = 1;
3516 t->blocked = 1;
3517 if (waitqueue_active(&root->fs_info->transaction_blocked_wait))
3518 wake_up(&root->fs_info->transaction_blocked_wait);
3519
3520 t->blocked = 0;
3521 if (waitqueue_active(&root->fs_info->transaction_wait))
3522 wake_up(&root->fs_info->transaction_wait);
3523
3524 t->commit_done = 1;
3525 if (waitqueue_active(&t->commit_wait))
3526 wake_up(&t->commit_wait);
3527
3528 btrfs_destroy_pending_snapshots(t);
3529
3530 btrfs_destroy_delalloc_inodes(root);
3531
3532 spin_lock(&root->fs_info->trans_lock);
3533 root->fs_info->running_transaction = NULL;
3534 spin_unlock(&root->fs_info->trans_lock);
3535
3536 btrfs_destroy_marked_extents(root, &t->dirty_pages,
3537 EXTENT_DIRTY);
3538
3539 btrfs_destroy_pinned_extent(root,
3540 root->fs_info->pinned_extents);
3541
3542 atomic_set(&t->use_count, 0);
3543 list_del_init(&t->list);
3544 memset(t, 0, sizeof(*t));
3545 kmem_cache_free(btrfs_transaction_cachep, t);
3546 }
3547
3548 spin_lock(&root->fs_info->trans_lock);
3549 root->fs_info->trans_no_join = 0;
3550 spin_unlock(&root->fs_info->trans_lock);
3551 mutex_unlock(&root->fs_info->transaction_kthread_mutex);
3552
3553 return 0;
3554 }
3555
3556 static struct extent_io_ops btree_extent_io_ops = {
3557 .write_cache_pages_lock_hook = btree_lock_page_hook,
3558 .readpage_end_io_hook = btree_readpage_end_io_hook,
3559 .readpage_io_failed_hook = btree_io_failed_hook,
3560 .submit_bio_hook = btree_submit_bio_hook,
3561 /* note we're sharing with inode.c for the merge bio hook */
3562 .merge_bio_hook = btrfs_merge_bio_hook,
3563 };